refactor(show): split the key handler into grid, navigation and tool keys (S3776)

* fix(windows): keep the shortcut icon after an update (#1114)

The MSI's Start menu shortcut took its icon from the WiX <Icon>, which Windows
Installer caches under %APPDATA%\Microsoft\Installer\{ProductCode}\. Every
update is a major upgrade with a new ProductCode, so the old folder is deleted.
A taskbar pin is a copy of the shortcut that the update never touches, so it
kept pointing at the deleted file and lost its icon.

Drop the Icon from the shortcut so it shows the icon embedded in deckcraft.exe,
whose path survives updates. The <Icon> stays for ARPPRODUCTICON. A test keeps
shortcuts from naming an MSI icon again.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* contributors: credit Sofia Alves Figueredo by real name

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix(windows): make the Start menu shortcut non-advertised (#1114)

Addresses the review comment: without an MSI Icon, a non-advertised shortcut
targets the installed exe directly and takes its embedded icon.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* fix(windows): package.ps1 rejects a deckcraft.exe with no embedded icon (#1114)

The shortcuts now take the exe's own icon, and -SkipBuild packages an existing
exe that may come from a build without DECKCRAFT_REQUIRE_WINRES=1. Count its
icons with ExtractIconEx and stop before WiX when there are none.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -137,6 +137,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 
 | Date | What landed |
 |---|---|
+| 2026-10-25 | Windows installer: the Start menu shortcut takes the icon embedded in `deckcraft.exe` instead of an MSI `<Icon>`, so a taskbar pin keeps its icon after an update (#1114); a pin that already lost it has to be unpinned and pinned again once |
 | 2026-10-24 | AutoFormat as you type: a paragraph that starts with `*`, `-`, `--`, `>`, `<>`, `1.`, `1)`, `I.`, `i.`, `A.`, `a.` or `a)` and a space or tab becomes a bulleted or numbered list in that style; Backspace right after puts the typed text back, and Tools ▸ AutoCorrect and `text.autocorrect {lists}` turn it off |
 | 2026-10-24 | Tables: while the caret is in a cell, dragging into another cell selects that range of cells (shaded, merged cells taken in whole), and Shift+arrow grows or shrinks it; formatting applies to the selected cells only, and Delete clears their text and keeps the table |
 | 2026-10-24 | Preferences ▸ Measurement units: inches or centimetres. The Format pane's Size and Position fields, Shape Format ▸ Size on the ribbon, the Slide Size dialog and the ruler show and take the chosen unit; the deck still stores points (#1326) |
@@ -293,6 +294,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-25 | trivial | Progress log: Windows shortcut icon survives updates (#1114). Scores and milestone names unchanged |
 | 2026-10-24 | trivial | Progress log: selecting a range of table cells by dragging. Scores and milestone names unchanged |
 | 2026-10-24 | trivial | Progress log: measurement units in centimetres (#1326). Scores unchanged |
 | 2026-10-22 | trivial | Progress log: Animation Pane ▸ Play From. Scores unchanged |

apps/deckcraft/src/main.rs

@@ -430,4 +430,27 @@ mod tests {
         assert_eq!(mac, win, "macOS and Windows offer different file types");
         assert_eq!(mac, linux, "macOS and Linux offer different file types");
     }
+
+    /// #1114: a shortcut that names an MSI `<Icon>` shows a blank icon once an update deletes the
+    /// cached copy of it, and a taskbar pin (a copy of the shortcut) is never repaired. Shortcuts
+    /// take the icon embedded in `deckcraft.exe`; only `ARPPRODUCTICON` uses the MSI `<Icon>`.
+    #[test]
+    fn windows_shortcuts_use_the_icon_embedded_in_the_exe() {
+        let wxs = include_str!("../../../packaging/windows/deckcraft.wxs");
+        let shortcuts: Vec<&str> = wxs.split("<Shortcut").skip(1).filter_map(|s| s.split("/>").next()).collect();
+        assert!(!shortcuts.is_empty(), "deckcraft.wxs has no shortcut");
+        for shortcut in shortcuts {
+            assert!(!shortcut.contains("Icon="), "a shortcut names an MSI <Icon>:{shortcut}");
+        }
+        assert!(wxs.contains("<Property Id=\"ARPPRODUCTICON\""), "Apps and features keeps its icon");
+    }
+
+    /// The shortcuts take the exe's own icon, and `package.ps1 -SkipBuild` packages an existing
+    /// exe without `DECKCRAFT_REQUIRE_WINRES`, so the script has to refuse one with no icon.
+    #[test]
+    fn the_windows_package_script_rejects_an_exe_without_an_icon() {
+        let script = include_str!("../../../packaging/windows/package.ps1");
+        assert!(script.contains("ExtractIconEx"), "package.ps1 does not count the exe's icons");
+        assert!(script.contains("has no embedded icon"), "package.ps1 does not reject an iconless exe");
+    }
 }

contributors/people.toml

@@ -65,3 +65,6 @@ sync_github_name = true
 
 [people.Katacc]
 sync_github_name = true
+
+[people.SofiaAFigueredo]
+real_name = "Sofia Alves Figueredo"

crates/av1/src/cdef.rs

@@ -45,7 +45,7 @@ fn cdef_block(fs: &FrameState, out: &mut FrameBuf, r: usize, c: usize, idx: usiz
     let var_str = if (var >> 6) != 0 { (31 - ((var >> 6) as u32).leading_zeros()).min(12) as i32 } else { 0 };
     pri = if var != 0 { (pri * (4 + var_str) + 8) >> 4 } else { 0 };
     let damping = cp.damping as i32 + coeff_shift as i32;
-    filter(fs, out, 0, r, c, pri, sec, damping, dir);
+    filter(fs, out, 0, (r, c), (pri, sec), damping, dir);
     if fs.num_planes == 1 {
         return true;
     }
@@ -53,8 +53,8 @@ fn cdef_block(fs: &FrameState, out: &mut FrameBuf, r: usize, c: usize, idx: usiz
     let sec = (cp.uv_sec[idx] << coeff_shift) as i32;
     let dir = if pri == 0 { 0 } else { CDEF_UV_DIR[fs.ssx][fs.ssy][y_dir] as usize };
     let damping = cp.damping as i32 + coeff_shift as i32 - 1;
-    filter(fs, out, 1, r, c, pri, sec, damping, dir);
-    filter(fs, out, 2, r, c, pri, sec, damping, dir);
+    filter(fs, out, 1, (r, c), (pri, sec), damping, dir);
+    filter(fs, out, 2, (r, c), (pri, sec), damping, dir);
     true
 }
 
@@ -124,33 +124,74 @@ fn constrain(diff: i32, threshold: i32, adj: u32) -> i32 {
     if diff < 0 { -mag } else { mag }
 }
 
-#[allow(clippy::too_many_arguments)]
-fn filter(fs: &FrameState, out: &mut FrameBuf, plane: usize, r: usize, c: usize, pri: i32, sec: i32, damping: i32, dir: usize) {
-    if pri == 0 && sec == 0 {
-        // Every tap contributes 0 and the clamp to [min, max] keeps x: CdefFrame = CurrFrame.
-        return;
+/// Tap offsets, weights and strengths of one block.
+struct Taps {
+    pri: i32,
+    sec: i32,
+    pri_adj: u32,
+    sec_adj: u32,
+    pri_off: [isize; 2],
+    sec_off: [[isize; 2]; 2],
+    pri_taps: [i32; 2],
+    sec_taps: [i32; 2],
+}
+
+impl Taps {
+    fn new(coeff_shift: u32, (pri, sec): (i32, i32), damping: i32, dir: usize) -> Taps {
+        let pri_tap = ((pri >> coeff_shift) & 1) as usize;
+        let off = |d: usize, k: usize| CDEF_DIRECTIONS[d][k][0] as isize * PAD_STRIDE as isize + CDEF_DIRECTIONS[d][k][1] as isize;
+        let pri_off = [off(dir, 0), off(dir, 1)];
+        let d_lo = (dir + 6) & 7;
+        let d_hi = (dir + 2) & 7;
+        let sec_off = [[off(d_lo, 0), off(d_hi, 0)], [off(d_lo, 1), off(d_hi, 1)]];
+        let pri_taps = [CDEF_PRI_TAPS[pri_tap][0] as i32, CDEF_PRI_TAPS[pri_tap][1] as i32];
+        let sec_taps = [CDEF_SEC_TAPS[pri_tap][0] as i32, CDEF_SEC_TAPS[pri_tap][1] as i32];
+        let adj = |t: i32| if t == 0 { 0 } else { (damping - (31 - (t as u32).leading_zeros()) as i32).max(0) as u32 };
+        Taps { pri, sec, pri_adj: adj(pri), sec_adj: adj(sec), pri_off, sec_off, pri_taps, sec_taps }
     }
-    let coeff_shift = fs.bit_depth - 8;
+
+    /// The 12 (offset, weight, strength, adjustment) taps in filtering order.
+    fn tap_list(&self) -> [(isize, i32, i32, u32); 12] {
+        let mut taps = [(0isize, 0i32, 0i32, 0u32); 12];
+        let mut n = 0;
+        for k in 0..2 {
+            for sign in [-1isize, 1] {
+                taps[n] = (sign * self.pri_off[k], self.pri_taps[k], self.pri, self.pri_adj);
+                taps[n + 1] = (sign * self.sec_off[k][0], self.sec_taps[k], self.sec, self.sec_adj);
+                taps[n + 2] = (sign * self.sec_off[k][1], self.sec_taps[k], self.sec, self.sec_adj);
+                n += 3;
+            }
+        }
+        taps
+    }
+}
+
+/// Position and size of a block within its plane.
+#[derive(Clone, Copy)]
+struct BlockRect {
+    x0: usize,
+    y0: usize,
+    w: usize,
+    h: usize,
+}
+
+/// The block with two samples of padding on every side, plus whether every sample is available
+/// (CdefAvailable: its 4x4 block is inside the frame).
+fn padded_block(fs: &FrameState, plane: usize, src: &Plane, rect: BlockRect) -> ([i32; PAD_STRIDE * PAD_STRIDE], bool) {
     let (sub_x, sub_y) = if plane > 0 { (fs.ssx, fs.ssy) } else { (0, 0) };
-    let x0 = (c * 4) >> sub_x;
-    let y0 = (r * 4) >> sub_y;
-    let w = 8 >> sub_x;
-    let h = 8 >> sub_y;
-    let src = &fs.cur.planes[plane];
     let (mi_rows, mi_cols) = (fs.fh.mi_rows as isize, fs.fh.mi_cols as isize);
-    // CdefAvailable per sample: its 4x4 block is inside the frame.
     let mut buf = [CDEF_NA; PAD_STRIDE * PAD_STRIDE];
     let mut all_avail = true;
-    for i in 0..h + 4 {
-        let y = (y0 + i) as isize - 2;
+    for i in 0..rect.h + 4 {
+        let y = (rect.y0 + i) as isize - 2;
         let cand_r = (y << sub_y) >> 2;
         if y < 0 || cand_r >= mi_rows {
             all_avail = false;
             continue;
         }
         let row = src.row(y as usize);
-        for j in 0..w + 4 {
-            let x = (x0 + j) as isize - 2;
+        for j in 0..rect.w + 4 {
+            let x = (rect.x0 + j) as isize - 2;
             let cand_c = (x << sub_x) >> 2;
             if x >= 0 && cand_c < mi_cols {
                 buf[i * PAD_STRIDE + j] = row[x as usize] as i32;
@@ -159,70 +200,70 @@ fn filter(fs: &FrameState, out: &mut FrameBuf, plane: usize, r: usize, c: usize,
             }
         }
     }
-    let pri_tap = ((pri >> coeff_shift) & 1) as usize;
-    let off = |d: usize, k: usize| CDEF_DIRECTIONS[d][k][0] as isize * PAD_STRIDE as isize + CDEF_DIRECTIONS[d][k][1] as isize;
-    let pri_off = [off(dir, 0), off(dir, 1)];
-    let d_lo = (dir + 6) & 7;
-    let d_hi = (dir + 2) & 7;
-    let sec_off = [[off(d_lo, 0), off(d_hi, 0)], [off(d_lo, 1), off(d_hi, 1)]];
-    let pri_taps = [CDEF_PRI_TAPS[pri_tap][0] as i32, CDEF_PRI_TAPS[pri_tap][1] as i32];
-    let sec_taps = [CDEF_SEC_TAPS[pri_tap][0] as i32, CDEF_SEC_TAPS[pri_tap][1] as i32];
-    let adj = |t: i32| if t == 0 { 0 } else { (damping - (31 - (t as u32).leading_zeros()) as i32).max(0) as u32 };
-    let (pri_adj, sec_adj) = (adj(pri), adj(sec));
+    (buf, all_avail)
+}
+
+/// Filters one sample whose taps may be unavailable (CDEF_NA).
+fn filter_sample(buf: &[i32; PAD_STRIDE * PAD_STRIDE], taps: &Taps, ci: isize, x: i32) -> u16 {
+    let mut sum = 0i32;
+    let mut max = x;
+    let mut min = x;
+    for k in 0..2 {
+        for sign in [-1isize, 1] {
+            let p = buf[(ci + sign * taps.pri_off[k]) as usize];
+            if p != CDEF_NA {
+                if taps.pri != 0 {
+                    sum += taps.pri_taps[k] * constrain(p - x, taps.pri, taps.pri_adj);
+                }
+                max = max.max(p);
+                min = min.min(p);
+            }
+            for s in 0..2 {
+                let q = buf[(ci + sign * taps.sec_off[k][s]) as usize];
+                if q != CDEF_NA {
+                    if taps.sec != 0 {
+                        sum += taps.sec_taps[k] * constrain(q - x, taps.sec, taps.sec_adj);
+                    }
+                    max = max.max(q);
+                    min = min.min(q);
+                }
+            }
+        }
+    }
+    (x + ((8 + sum - (sum < 0) as i32) >> 4)).clamp(min, max) as u16
+}
+
+fn filter(fs: &FrameState, out: &mut FrameBuf, plane: usize, (r, c): (usize, usize), strengths: (i32, i32), damping: i32, dir: usize) {
+    let (pri, sec) = strengths;
+    if pri == 0 && sec == 0 {
+        // Every tap contributes 0 and the clamp to [min, max] keeps x: CdefFrame = CurrFrame.
+        return;
+    }
+    let coeff_shift = fs.bit_depth - 8;
+    let (sub_x, sub_y) = if plane > 0 { (fs.ssx, fs.ssy) } else { (0, 0) };
+    let rect = BlockRect { x0: (c * 4) >> sub_x, y0: (r * 4) >> sub_y, w: 8 >> sub_x, h: 8 >> sub_y };
+    let src = &fs.cur.planes[plane];
+    let (buf, all_avail) = padded_block(fs, plane, src, rect);
+    let taps = Taps::new(coeff_shift, strengths, damping, dir);
     let dst = &mut out.planes[plane];
     if all_avail {
         // Every tap is available: whole rows at a time (constrain() with threshold 0 is 0).
-        let mut taps = [(0isize, 0i32, 0i32, 0u32); 12];
-        let mut n = 0;
-        for k in 0..2 {
-            for sign in [-1isize, 1] {
-                taps[n] = (sign * pri_off[k], pri_taps[k], pri, pri_adj);
-                taps[n + 1] = (sign * sec_off[k][0], sec_taps[k], sec, sec_adj);
-                taps[n + 2] = (sign * sec_off[k][1], sec_taps[k], sec, sec_adj);
-                n += 3;
-            }
-        }
-        let rows = (y0, x0, h);
-        match w {
-            8 => filter_rows::<8>(&buf, &taps, dst, rows),
-            _ => filter_rows::<4>(&buf, &taps, dst, rows),
+        let list = taps.tap_list();
+        let rows = (rect.y0, rect.x0, rect.h);
+        match rect.w {
+            8 => filter_rows::<8>(&buf, &list, dst, rows),
+            _ => filter_rows::<4>(&buf, &list, dst, rows),
         }
         return;
     }
-    for i in 0..h {
+    for i in 0..rect.h {
         // The centre sample is read even where CdefAvailable is 0 (8x8 blocks straddling an odd
         // MiRows / MiCols edge).
-        let srow = &src.row(y0 + i)[x0..x0 + w];
-        let drow = &mut dst.row_mut(y0 + i)[x0..x0 + w];
-        for j in 0..w {
+        let srow = &src.row(rect.y0 + i)[rect.x0..rect.x0 + rect.w];
+        let drow = &mut dst.row_mut(rect.y0 + i)[rect.x0..rect.x0 + rect.w];
+        for j in 0..rect.w {
             let ci = ((i + 2) * PAD_STRIDE + j + 2) as isize;
-            let x = srow[j] as i32;
-            let mut sum = 0i32;
-            let mut max = x;
-            let mut min = x;
-            for k in 0..2 {
-                for sign in [-1isize, 1] {
-                    let p = buf[(ci + sign * pri_off[k]) as usize];
-                    if p != CDEF_NA {
-                        if pri != 0 {
-                            sum += pri_taps[k] * constrain(p - x, pri, pri_adj);
-                        }
-                        max = max.max(p);
-                        min = min.min(p);
-                    }
-                    for s in 0..2 {
-                        let q = buf[(ci + sign * sec_off[k][s]) as usize];
-                        if q != CDEF_NA {
-                            if sec != 0 {
-                                sum += sec_taps[k] * constrain(q - x, sec, sec_adj);
-                            }
-                            max = max.max(q);
-                            min = min.min(q);
-                        }
-                    }
-                }
-            }
-            drow[j] = (x + ((8 + sum - (sum < 0) as i32) >> 4)).clamp(min, max) as u16;
+            drow[j] = filter_sample(&buf, &taps, ci, srow[j] as i32);
         }
     }
 }

crates/av1/src/decoder.rs

@@ -405,49 +405,35 @@ impl Decoder {
         r
     }
 
+    /// Whether an OBU belongs to the selected operating point (spec 7.5: OBUs of other layers are dropped).
+    fn in_operating_point(&self, obu: &ObuUnit) -> bool {
+        if obu.obu_type != OBU_SEQUENCE_HEADER_T
+            && obu.obu_type != OBU_TEMPORAL_DELIMITER_T
+            && obu.ext
+            && let Some(seq) = &self.seq
+            && seq.op_idc != 0
+        {
+            let idc = seq.op_idc;
+            let in_t = (idc >> obu.temporal_id) & 1;
+            let in_s = (idc >> (obu.spatial_id + 8)) & 1;
+            if in_t == 0 || in_s == 0 {
+                return false;
+            }
+        }
+        true
+    }
+
     fn parse_obus(&mut self, data: &[u8], out: &mut Vec<(Output, usize, u32)>) -> Result<()> {
         let mut tu = 0usize;
         let mut pos = 0;
         while pos < data.len() {
-            let h = data[pos];
-            if h & 0x80 != 0 {
-                return Err(Error::Invalid("obu_forbidden_bit"));
+            let obu = parse_obu_unit(data, pos)?;
+            pos = obu.end;
+            if !self.in_operating_point(&obu) {
+                continue;
             }
-            let obu_type = ((h >> 3) & 0xf) as u32;
-            let ext = h & 4 != 0;
-            let has_size = h & 2 != 0;
-            let mut p = pos + 1;
-            let (mut temporal_id, mut spatial_id) = (0, 0);
-            if ext {
-                let e = *data.get(p).ok_or(Error::Truncated)?;
-                temporal_id = (e >> 5) as u32;
-                spatial_id = ((e >> 3) & 3) as u32;
-                p += 1;
-            }
-            let size = if has_size {
-                let (v, n) = leb128(data.get(p..).ok_or(Error::Truncated)?)?;
-                p += n;
-                v as usize
-            } else {
-                data.len().checked_sub(p).ok_or(Error::Truncated)?
-            };
-            let end = p.checked_add(size).filter(|&e| e <= data.len()).ok_or(Error::Truncated)?;
-            let payload = &data[p..end];
-            pos = end;
-            if obu_type != OBU_SEQUENCE_HEADER_T
-                && obu_type != OBU_TEMPORAL_DELIMITER_T
-                && ext
-                && let Some(seq) = &self.seq
-                && seq.op_idc != 0
-            {
-                let idc = seq.op_idc;
-                let in_t = (idc >> temporal_id) & 1;
-                let in_s = (idc >> (spatial_id + 8)) & 1;
-                if in_t == 0 || in_s == 0 {
-                    continue;
-                }
-            }
-            match obu_type {
+            let (payload, spatial_id) = (obu.payload, obu.spatial_id);
+            match obu.obu_type {
                 OBU_SEQUENCE_HEADER_T => {
                     let s = SequenceHeader::parse(payload)?;
                     self.seq = Some(s);
@@ -457,27 +443,11 @@ impl Decoder {
                     tu += 1;
                 }
                 OBU_FRAME_HEADER_T | OBU_REDUNDANT_FRAME_HEADER_T | OBU_FRAME_T => {
-                    if self.seen_frame_header {
-                        // frame_header_copy(): identical to the active header
-                        if obu_type != OBU_FRAME_T {
-                            continue;
-                        }
-                    }
-                    let mut r = BitReader::new(payload);
-                    let shown = self.frame_header(&mut r, temporal_id, spatial_id)?;
-                    if let Some(o) = shown {
+                    if let Some(o) = self.frame_obu(&obu)? {
                         if out.iter().filter(|(o, _, _)| matches!(o, Output::Existing { .. })).count() >= 32 {
                             return Err(Error::Invalid("too many frame outputs in chunk"));
                         }
                         out.push((o, tu, spatial_id));
-                        continue;
-                    }
-                    if obu_type == OBU_FRAME_T {
-                        r.byte_align();
-                        let rest = payload.get(r.byte_pos()..).ok_or(Error::Truncated)?;
-                        if let Some(o) = self.tile_group(rest)? {
-                            out.push((o, tu, spatial_id));
-                        }
                     }
                 }
                 OBU_TILE_GROUP_T => {
@@ -492,6 +462,22 @@ impl Decoder {
         Ok(())
     }
 
+    /// A frame header or frame OBU: returns the picture it completes, if any.
+    fn frame_obu(&mut self, obu: &ObuUnit) -> Result<Option<Output>> {
+        // frame_header_copy(): identical to the active header
+        if self.seen_frame_header && obu.obu_type != OBU_FRAME_T {
+            return Ok(None);
+        }
+        let mut r = BitReader::new(obu.payload);
+        let shown = self.frame_header(&mut r, obu.temporal_id, obu.spatial_id)?;
+        if shown.is_some() || obu.obu_type != OBU_FRAME_T {
+            return Ok(shown);
+        }
+        r.byte_align();
+        let rest = obu.payload.get(r.byte_pos()..).ok_or(Error::Truncated)?;
+        self.tile_group(rest)
+    }
+
     /// frame_header_obu( ): returns the output for show_existing_frame.
     fn frame_header(&mut self, r: &mut BitReader, temporal_id: u32, spatial_id: u32) -> Result<Option<Output>> {
         let seq = self.seq.clone().ok_or(Error::Invalid("frame before sequence header"))?;
@@ -1017,6 +1003,43 @@ mod tests {
     }
 }
 
+/// One OBU: its header fields, payload and the position just past it.
+struct ObuUnit<'a> {
+    obu_type: u32,
+    ext: bool,
+    temporal_id: u32,
+    spatial_id: u32,
+    payload: &'a [u8],
+    end: usize,
+}
+
+fn parse_obu_unit(data: &[u8], pos: usize) -> Result<ObuUnit<'_>> {
+    let h = data[pos];
+    if h & 0x80 != 0 {
+        return Err(Error::Invalid("obu_forbidden_bit"));
+    }
+    let obu_type = ((h >> 3) & 0xf) as u32;
+    let ext = h & 4 != 0;
+    let has_size = h & 2 != 0;
+    let mut p = pos + 1;
+    let (mut temporal_id, mut spatial_id) = (0, 0);
+    if ext {
+        let e = *data.get(p).ok_or(Error::Truncated)?;
+        temporal_id = (e >> 5) as u32;
+        spatial_id = ((e >> 3) & 3) as u32;
+        p += 1;
+    }
+    let size = if has_size {
+        let (v, n) = leb128(data.get(p..).ok_or(Error::Truncated)?)?;
+        p += n;
+        v as usize
+    } else {
+        data.len().checked_sub(p).ok_or(Error::Truncated)?
+    };
+    let end = p.checked_add(size).filter(|&e| e <= data.len()).ok_or(Error::Truncated)?;
+    Ok(ObuUnit { obu_type, ext, temporal_id, spatial_id, payload: &data[p..end], end })
+}
+
 #[cfg(test)]
 mod guard_tests {
     use super::*;

crates/av1/src/grain.rs

@@ -55,21 +55,79 @@ impl Rng {
     }
 }
 
-pub(crate) fn apply(pic: &mut Picture, g: &FilmGrainParams, seq: &SequenceHeader) {
-    let _ = seq;
-    let bd = pic.bit_depth as u32;
-    let mono = pic.mono_chrome;
-    let num_planes = if mono { 1 } else { 3 };
-    let (sub_x, sub_y) = (pic.subsampling_x as usize, pic.subsampling_y as usize);
-    let w = pic.width as usize;
-    let h = pic.height as usize;
-    let grain_center = 128i32 << (bd - 8);
-    let grain_min = -grain_center;
-    let grain_max = (256i32 << (bd - 8)) - 1 - grain_center;
+/// Picture-level parameters shared by the grain synthesis stages.
+struct GrainCtx<'a> {
+    g: &'a FilmGrainParams,
+    bd: u32,
+    mono: bool,
+    sub_x: usize,
+    sub_y: usize,
+    w: usize,
+    h: usize,
+    grain_min: i32,
+    grain_max: i32,
+}
 
-    // Generate grain (7.18.3.3).
-    let mut rng = Rng(g.grain_seed);
-    let shift = 12 - bd + g.grain_scale_shift;
+impl GrainCtx<'_> {
+    fn num_planes(&self) -> usize {
+        if self.mono { 1 } else { 3 }
+    }
+
+    fn grain_shift(&self) -> u32 {
+        12 - self.bd + self.g.grain_scale_shift
+    }
+
+    fn ar_shift(&self) -> u32 {
+        self.g.ar_coeff_shift_minus_6 + 6
+    }
+
+    fn lag(&self) -> i32 {
+        self.g.ar_coeff_lag as i32
+    }
+
+    fn stripe_w(&self) -> usize {
+        self.w + 64
+    }
+}
+
+type GrainTemplate = Vec<[i32; 82]>;
+
+/// The luma, Cb and Cr grain templates (7.18.3.3).
+struct Templates {
+    luma: GrainTemplate,
+    cb: GrainTemplate,
+    cr: GrainTemplate,
+}
+
+impl Templates {
+    fn plane(&self, plane: usize) -> &GrainTemplate {
+        match plane {
+            0 => &self.luma,
+            1 => &self.cb,
+            _ => &self.cr,
+        }
+    }
+}
+
+fn luma_ar_sum(g: &FilmGrainParams, luma: &[[i32; 82]], lag: i32, y: usize, x: usize) -> i32 {
+    let mut s = 0;
+    let mut pos = 0;
+    'outer: for dr in -lag..=0 {
+        for dc in -lag..=lag {
+            if dr == 0 && dc == 0 {
+                break 'outer;
+            }
+            let c = g.ar_coeffs_y_plus_128[pos] as i32 - 128;
+            s += luma[(y as i32 + dr) as usize][(x as i32 + dc) as usize] * c;
+            pos += 1;
+        }
+    }
+    s
+}
+
+fn luma_grain(c: &GrainCtx, rng: &mut Rng) -> GrainTemplate {
+    let g = c.g;
+    let shift = c.grain_shift();
     let mut luma = vec![[0i32; 82]; 73];
     for row in luma.iter_mut() {
         for v in row.iter_mut() {
@@ -77,77 +135,89 @@ pub(crate) fn apply(pic: &mut Picture, g: &FilmGrainParams, seq: &SequenceHeader
             *v = round2(gv, shift);
         }
     }
-    let ar_shift = g.ar_coeff_shift_minus_6 + 6;
-    let lag = g.ar_coeff_lag as i32;
+    let ar_shift = c.ar_shift();
+    let lag = c.lag();
     for y in 3..73 {
         for x in 3..82 - 3 {
-            let mut s = 0;
-            let mut pos = 0;
-            'outer: for dr in -lag..=0 {
-                for dc in -lag..=lag {
-                    if dr == 0 && dc == 0 {
-                        break 'outer;
-                    }
-                    let c = g.ar_coeffs_y_plus_128[pos] as i32 - 128;
-                    s += luma[(y as i32 + dr) as usize][(x as i32 + dc) as usize] * c;
-                    pos += 1;
-                }
-            }
-            luma[y][x] = (luma[y][x] + round2(s, ar_shift)).clamp(grain_min, grain_max);
-        }
-    }
-    let chroma_w = if sub_x != 0 { 44 } else { 82 };
-    let chroma_h = if sub_y != 0 { 38 } else { 73 };
-    let mut cb = vec![[0i32; 82]; 73];
-    let mut cr = vec![[0i32; 82]; 73];
-    if !mono {
-        for (arr, seed, on) in [(&mut cb, 0xb524u32, g.num_cb_points > 0), (&mut cr, 0x49d8, g.num_cr_points > 0)] {
-            rng.0 = g.grain_seed ^ seed;
-            for row in arr.iter_mut().take(chroma_h) {
-                for v in row.iter_mut().take(chroma_w) {
-                    let gv = if on || g.chroma_scaling_from_luma { GAUSSIAN_SEQUENCE[rng.next(11) as usize] as i32 } else { 0 };
-                    *v = round2(gv, shift);
-                }
-            }
-        }
-        for y in 3..chroma_h {
-            for x in 3..chroma_w - 3 {
-                let mut s0 = 0;
-                let mut s1 = 0;
-                let mut pos = 0;
-                'outer: for dr in -lag..=0 {
-                    for dc in -lag..=lag {
-                        let c0 = g.ar_coeffs_cb_plus_128[pos] as i32 - 128;
-                        let c1 = g.ar_coeffs_cr_plus_128[pos] as i32 - 128;
-                        if dr == 0 && dc == 0 {
-                            if g.num_y_points > 0 {
-                                let mut l = 0;
-                                let lx = ((x - 3) << sub_x) + 3;
-                                let ly = ((y - 3) << sub_y) + 3;
-                                for i in 0..=sub_y {
-                                    for j in 0..=sub_x {
-                                        l += luma[ly + i][lx + j];
-                                    }
-                                }
-                                let l = round2(l, (sub_x + sub_y) as u32);
-                                s0 += l * c0;
-                                s1 += l * c1;
-                            }
-                            break 'outer;
-                        }
-                        let (yy, xx) = ((y as i32 + dr) as usize, (x as i32 + dc) as usize);
-                        s0 += cb[yy][xx] * c0;
-                        s1 += cr[yy][xx] * c1;
-                        pos += 1;
-                    }
-                }
-                cb[y][x] = (cb[y][x] + round2(s0, ar_shift)).clamp(grain_min, grain_max);
-                cr[y][x] = (cr[y][x] + round2(s1, ar_shift)).clamp(grain_min, grain_max);
-            }
+            let s = luma_ar_sum(g, &luma, lag, y, x);
+            luma[y][x] = (luma[y][x] + round2(s, ar_shift)).clamp(c.grain_min, c.grain_max);
         }
     }
+    luma
+}
 
-    // Scaling lookup (7.18.3.4).
+/// The luma contribution to the chroma autoregressive filter at chroma position (y, x).
+fn chroma_luma_term(c: &GrainCtx, luma: &[[i32; 82]], y: usize, x: usize) -> i32 {
+    let mut l = 0;
+    let lx = ((x - 3) << c.sub_x) + 3;
+    let ly = ((y - 3) << c.sub_y) + 3;
+    for i in 0..=c.sub_y {
+        for j in 0..=c.sub_x {
+            l += luma[ly + i][lx + j];
+        }
+    }
+    round2(l, (c.sub_x + c.sub_y) as u32)
+}
+
+fn chroma_ar_sums(c: &GrainCtx, t: &Templates, y: usize, x: usize) -> (i32, i32) {
+    let g = c.g;
+    let lag = c.lag();
+    let mut s0 = 0;
+    let mut s1 = 0;
+    let mut pos = 0;
+    'outer: for dr in -lag..=0 {
+        for dc in -lag..=lag {
+            let c0 = g.ar_coeffs_cb_plus_128[pos] as i32 - 128;
+            let c1 = g.ar_coeffs_cr_plus_128[pos] as i32 - 128;
+            if dr == 0 && dc == 0 {
+                if g.num_y_points > 0 {
+                    let l = chroma_luma_term(c, &t.luma, y, x);
+                    s0 += l * c0;
+                    s1 += l * c1;
+                }
+                break 'outer;
+            }
+            let (yy, xx) = ((y as i32 + dr) as usize, (x as i32 + dc) as usize);
+            s0 += t.cb[yy][xx] * c0;
+            s1 += t.cr[yy][xx] * c1;
+            pos += 1;
+        }
+    }
+    (s0, s1)
+}
+
+/// Chroma grain templates; zero for monochrome pictures.
+fn chroma_grain(c: &GrainCtx, rng: &mut Rng, luma: GrainTemplate) -> Templates {
+    let g = c.g;
+    let mut t = Templates { luma, cb: vec![[0i32; 82]; 73], cr: vec![[0i32; 82]; 73] };
+    if c.mono {
+        return t;
+    }
+    let shift = c.grain_shift();
+    let ar_shift = c.ar_shift();
+    let chroma_w = if c.sub_x != 0 { 44 } else { 82 };
+    let chroma_h = if c.sub_y != 0 { 38 } else { 73 };
+    for (arr, seed, on) in [(&mut t.cb, 0xb524u32, g.num_cb_points > 0), (&mut t.cr, 0x49d8, g.num_cr_points > 0)] {
+        rng.0 = g.grain_seed ^ seed;
+        for row in arr.iter_mut().take(chroma_h) {
+            for v in row.iter_mut().take(chroma_w) {
+                let gv = if on || g.chroma_scaling_from_luma { GAUSSIAN_SEQUENCE[rng.next(11) as usize] as i32 } else { 0 };
+                *v = round2(gv, shift);
+            }
+        }
+    }
+    for y in 3..chroma_h {
+        for x in 3..chroma_w - 3 {
+            let (s0, s1) = chroma_ar_sums(c, &t, y, x);
+            t.cb[y][x] = (t.cb[y][x] + round2(s0, ar_shift)).clamp(c.grain_min, c.grain_max);
+            t.cr[y][x] = (t.cr[y][x] + round2(s1, ar_shift)).clamp(c.grain_min, c.grain_max);
+        }
+    }
+    t
+}
+
+/// Scaling lookup tables (7.18.3.4), one per plane.
+fn scaling_luts(g: &FilmGrainParams, num_planes: usize) -> [[i32; 256]; 3] {
     let mut lut = [[0i32; 256]; 3];
     for (plane, l) in lut.iter_mut().enumerate().take(num_planes) {
         let (n, xs, ys) = if plane == 0 || g.chroma_scaling_from_luma {
@@ -159,101 +229,141 @@ pub(crate) fn apply(pic: &mut Picture, g: &FilmGrainParams, seq: &SequenceHeader
         };
         *l = scaling_lut(n, xs, ys);
     }
-    let scale_lut = |plane: usize, index: i32| -> i32 {
-        let sh = bd - 8;
-        let x = index >> sh;
-        let rem = index - (x << sh);
-        if bd == 8 || x == 255 {
-            lut[plane][x as usize]
-        } else {
-            let start = lut[plane][x as usize];
-            let end = lut[plane][x as usize + 1];
-            start + round2((end - start) * rem, sh)
-        }
-    };
+    lut
+}
 
-    // Noise stripes (7.18.3.5).
-    let stripe_w = w + 64;
-    let n_stripes = (h.div_ceil(2)).div_ceil(16).max(1);
-    let mut stripes: Vec<[Vec<i32>; 3]> = (0..n_stripes).map(|_| [vec![0; 34 * stripe_w], vec![0; 34 * stripe_w], vec![0; 34 * stripe_w]]).collect();
-    let overlap = g.overlap_flag;
-    for (luma_num, stripe) in stripes.iter_mut().enumerate() {
-        let mut r = g.grain_seed;
-        r ^= (((luma_num * 37 + 178) & 255) << 8) as u32;
-        r ^= ((luma_num * 173 + 105) & 255) as u32;
-        rng.0 = r;
-        let mut x = 0;
-        while x < w.div_ceil(2) {
-            let rand = rng.next(8) as usize;
-            let off_x = rand >> 4;
-            let off_y = rand & 15;
-            for (plane, s) in stripe.iter_mut().enumerate().take(num_planes) {
-                let psx = if plane > 0 { sub_x } else { 0 };
-                let psy = if plane > 0 { sub_y } else { 0 };
-                let pox = if psx != 0 { 6 + off_x } else { 9 + off_x * 2 };
-                let poy = if psy != 0 { 6 + off_y } else { 9 + off_y * 2 };
-                let src = match plane {
-                    0 => &luma,
-                    1 => &cb,
-                    _ => &cr,
+fn scale_lookup(lut: &[[i32; 256]; 3], bd: u32, plane: usize, index: i32) -> i32 {
+    let sh = bd - 8;
+    let x = index >> sh;
+    let rem = index - (x << sh);
+    if bd == 8 || x == 255 {
+        lut[plane][x as usize]
+    } else {
+        let start = lut[plane][x as usize];
+        let end = lut[plane][x as usize + 1];
+        start + round2((end - start) * rem, sh)
+    }
+}
+
+/// Fills one plane of a noise stripe from the grain template at stripe column `x`.
+fn fill_stripe_plane(c: &GrainCtx, src: &GrainTemplate, s: &mut [i32], plane: usize, offsets: (usize, usize), x: usize) {
+    let (off_x, off_y) = offsets;
+    let stripe_w = c.stripe_w();
+    let overlap = c.g.overlap_flag;
+    let psx = if plane > 0 { c.sub_x } else { 0 };
+    let psy = if plane > 0 { c.sub_y } else { 0 };
+    let pox = if psx != 0 { 6 + off_x } else { 9 + off_x * 2 };
+    let poy = if psy != 0 { 6 + off_y } else { 9 + off_y * 2 };
+    for i in 0..(34 >> psy) {
+        for j in 0..(34 >> psx) {
+            let mut gv = src[poy + i][pox + j];
+            let (idx, blend) = if psx == 0 { (i * stripe_w + x * 2 + j, j < 2) } else { (i * stripe_w + x + j, j == 0) };
+            if blend && overlap && x > 0 {
+                let old = s[idx];
+                gv = if psx != 0 {
+                    old * 23 + gv * 22
+                } else if j == 0 {
+                    old * 27 + gv * 17
+                } else {
+                    old * 17 + gv * 27
                 };
-                for i in 0..(34 >> psy) {
-                    for j in 0..(34 >> psx) {
-                        let mut gv = src[poy + i][pox + j];
-                        if psx == 0 {
-                            let idx = i * stripe_w + x * 2 + j;
-                            if j < 2 && overlap && x > 0 {
-                                let old = s[idx];
-                                gv = if j == 0 { old * 27 + gv * 17 } else { old * 17 + gv * 27 };
-                                gv = round2(gv, 5).clamp(grain_min, grain_max);
-                            }
-                            s[idx] = gv;
-                        } else {
-                            let idx = i * stripe_w + x + j;
-                            if j == 0 && overlap && x > 0 {
-                                let old = s[idx];
-                                gv = round2(old * 23 + gv * 22, 5).clamp(grain_min, grain_max);
-                            }
-                            s[idx] = gv;
-                        }
-                    }
-                }
+                gv = round2(gv, 5).clamp(c.grain_min, c.grain_max);
             }
-            x += 16;
+            s[idx] = gv;
         }
     }
-    let noise_at = |plane: usize, y: usize, x: usize| -> i32 {
-        let psy = if plane > 0 { sub_y } else { 0 };
+}
+
+/// Noise stripes (7.18.3.5).
+struct Stripes {
+    data: Vec<[Vec<i32>; 3]>,
+    stripe_w: usize,
+    overlap: bool,
+    sub_y: usize,
+    grain_min: i32,
+    grain_max: i32,
+}
+
+impl Stripes {
+    fn build(c: &GrainCtx, t: &Templates, rng: &mut Rng) -> Stripes {
+        let g = c.g;
+        let stripe_w = c.stripe_w();
+        let n_stripes = (c.h.div_ceil(2)).div_ceil(16).max(1);
+        let mut data: Vec<[Vec<i32>; 3]> = (0..n_stripes).map(|_| [vec![0; 34 * stripe_w], vec![0; 34 * stripe_w], vec![0; 34 * stripe_w]]).collect();
+        for (luma_num, stripe) in data.iter_mut().enumerate() {
+            let mut r = g.grain_seed;
+            r ^= (((luma_num * 37 + 178) & 255) << 8) as u32;
+            r ^= ((luma_num * 173 + 105) & 255) as u32;
+            rng.0 = r;
+            let mut x = 0;
+            while x < c.w.div_ceil(2) {
+                let rand = rng.next(8) as usize;
+                let offsets = (rand >> 4, rand & 15);
+                for (plane, s) in stripe.iter_mut().enumerate().take(c.num_planes()) {
+                    fill_stripe_plane(c, t.plane(plane), s, plane, offsets, x);
+                }
+                x += 16;
+            }
+        }
+        Stripes { data, stripe_w, overlap: g.overlap_flag, sub_y: c.sub_y, grain_min: c.grain_min, grain_max: c.grain_max }
+    }
+
+    fn noise_at(&self, plane: usize, y: usize, x: usize) -> i32 {
+        let psy = if plane > 0 { self.sub_y } else { 0 };
         let luma_num = y >> (5 - psy);
         let i = y - (luma_num << (5 - psy));
-        let mut gv = stripes[luma_num][plane][i * stripe_w + x];
+        let mut gv = self.data[luma_num][plane][i * self.stripe_w + x];
         if psy == 0 {
-            if i < 2 && luma_num > 0 && overlap {
-                let old = stripes[luma_num - 1][plane][(i + 32) * stripe_w + x];
+            if i < 2 && luma_num > 0 && self.overlap {
+                let old = self.data[luma_num - 1][plane][(i + 32) * self.stripe_w + x];
                 gv = if i == 0 { old * 27 + gv * 17 } else { old * 17 + gv * 27 };
-                gv = round2(gv, 5).clamp(grain_min, grain_max);
+                gv = round2(gv, 5).clamp(self.grain_min, self.grain_max);
             }
-        } else if i < 1 && luma_num > 0 && overlap {
-            let old = stripes[luma_num - 1][plane][(i + 16) * stripe_w + x];
-            gv = round2(old * 23 + gv * 22, 5).clamp(grain_min, grain_max);
+        } else if i < 1 && luma_num > 0 && self.overlap {
+            let old = self.data[luma_num - 1][plane][(i + 16) * self.stripe_w + x];
+            gv = round2(old * 23 + gv * 22, 5).clamp(self.grain_min, self.grain_max);
         }
         gv
-    };
+    }
+}
 
-    // Blend (7.18.3.5).
-    let (min_value, max_luma, max_chroma) = if g.clip_to_restricted_range {
-        let ml = 235 << (bd - 8);
-        (16 << (bd - 8), ml, if pic.matrix_coefficients as usize == MC_IDENTITY { ml } else { 240 << (bd - 8) })
-    } else {
-        let m = (256 << (bd - 8)) - 1;
-        (0, m, m)
-    };
-    let pix_max = (1i32 << bd) - 1;
-    let scaling_shift = g.grain_scaling_minus_8 + 8;
-    if !mono {
+/// Output clipping range and scaling shift for the blend step (7.18.3.5).
+struct BlendRange {
+    min_value: i32,
+    max_luma: i32,
+    max_chroma: i32,
+    pix_max: i32,
+    scaling_shift: u32,
+}
+
+impl BlendRange {
+    fn new(c: &GrainCtx, matrix_coefficients: usize) -> BlendRange {
+        let bd = c.bd;
+        let (min_value, max_luma, max_chroma) = if c.g.clip_to_restricted_range {
+            let ml = 235 << (bd - 8);
+            (16 << (bd - 8), ml, if matrix_coefficients == MC_IDENTITY { ml } else { 240 << (bd - 8) })
+        } else {
+            let m = (256 << (bd - 8)) - 1;
+            (0, m, m)
+        };
+        BlendRange { min_value, max_luma, max_chroma, pix_max: (1i32 << bd) - 1, scaling_shift: c.g.grain_scaling_minus_8 + 8 }
+    }
+}
+
+struct BlendEnv<'a> {
+    c: &'a GrainCtx<'a>,
+    lut: &'a [[i32; 256]; 3],
+    stripes: &'a Stripes,
+    range: &'a BlendRange,
+}
+
+impl BlendEnv<'_> {
+    fn blend_chroma(&self, py: &[u16], pu: &mut [u16], pv: &mut [u16]) {
+        let c = self.c;
+        let g = c.g;
+        let (w, h, sub_x, sub_y, bd) = (c.w, c.h, c.sub_x, c.sub_y, c.bd);
         let cw = (w + sub_x) >> sub_x;
         let ch = (h + sub_y) >> sub_y;
-        let [py, pu, pv] = &mut pic.planes;
         for y in 0..ch {
             for x in 0..cw {
                 let lx = x << sub_x;
@@ -272,26 +382,62 @@ pub(crate) fn apply(pic: &mut Picture, g: &FilmGrainParams, seq: &SequenceHeader
                         avg
                     } else {
                         let combined = avg * (luma_mult as i32 - 128) + orig * (mult as i32 - 128);
-                        ((combined >> 6) + ((offset as i32 - 256) << (bd - 8))).clamp(0, pix_max)
+                        ((combined >> 6) + ((offset as i32 - 256) << (bd - 8))).clamp(0, self.range.pix_max)
                     };
-                    let noise = round2(scale_lut(plane, merged) * noise_at(plane, y, x), scaling_shift);
-                    out[y * cw + x] = (orig + noise).clamp(min_value, max_chroma) as u16;
+                    let noise = round2(scale_lookup(self.lut, bd, plane, merged) * self.stripes.noise_at(plane, y, x), self.range.scaling_shift);
+                    out[y * cw + x] = (orig + noise).clamp(self.range.min_value, self.range.max_chroma) as u16;
                 }
             }
         }
     }
-    if g.num_y_points > 0 {
-        let py = &mut pic.planes[0];
+
+    fn blend_luma(&self, py: &mut [u16]) {
+        let (w, h) = (self.c.w, self.c.h);
         for y in 0..h {
             for x in 0..w {
                 let orig = py[y * w + x] as i32;
-                let noise = round2(scale_lut(0, orig) * noise_at(0, y, x), scaling_shift);
-                py[y * w + x] = (orig + noise).clamp(min_value, max_luma) as u16;
+                let noise = round2(scale_lookup(self.lut, self.c.bd, 0, orig) * self.stripes.noise_at(0, y, x), self.range.scaling_shift);
+                py[y * w + x] = (orig + noise).clamp(self.range.min_value, self.range.max_luma) as u16;
             }
         }
     }
 }
 
+pub(crate) fn apply(pic: &mut Picture, g: &FilmGrainParams, seq: &SequenceHeader) {
+    let _ = seq;
+    let bd = pic.bit_depth as u32;
+    let grain_center = 128i32 << (bd - 8);
+    let c = GrainCtx {
+        g,
+        bd,
+        mono: pic.mono_chrome,
+        sub_x: pic.subsampling_x as usize,
+        sub_y: pic.subsampling_y as usize,
+        w: pic.width as usize,
+        h: pic.height as usize,
+        grain_min: -grain_center,
+        grain_max: (256i32 << (bd - 8)) - 1 - grain_center,
+    };
+
+    // Generate grain (7.18.3.3).
+    let mut rng = Rng(g.grain_seed);
+    let luma = luma_grain(&c, &mut rng);
+    let templates = chroma_grain(&c, &mut rng, luma);
+    let lut = scaling_luts(g, c.num_planes());
+    let stripes = Stripes::build(&c, &templates, &mut rng);
+
+    // Blend (7.18.3.5).
+    let range = BlendRange::new(&c, pic.matrix_coefficients as usize);
+    let env = BlendEnv { c: &c, lut: &lut, stripes: &stripes, range: &range };
+    if !c.mono {
+        let [py, pu, pv] = &mut pic.planes;
+        env.blend_chroma(py, pu, pv);
+    }
+    if g.num_y_points > 0 {
+        env.blend_luma(&mut pic.planes[0]);
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/av1/src/restoration.rs

@@ -73,57 +73,70 @@ impl LrCtx<'_> {
     }
 }
 
+/// Position and size of a (at most 4x4) restoration block within its plane.
+#[derive(Clone, Copy)]
+struct LrBlock {
+    x: i32,
+    y: i32,
+    w: i32,
+    h: i32,
+}
+
 /// Loop restoration (7.17): returns LrFrame given UpscaledCurrFrame and UpscaledCdefFrame.
 pub(crate) fn loop_restoration(fs: &FrameState, cur: &FrameBuf, cdef: &FrameBuf) -> FrameBuf {
-    let fh = &fs.fh;
     let mut lr = cdef.clone();
-    let up_w = fh.upscaled_width as i32;
-    let fr_h = fh.frame_height as i32;
-    let bd = fs.bit_depth;
     for plane in 0..fs.num_planes {
-        let rtype_frame = fh.lr.frame_restoration_type[plane];
-        if rtype_frame == RESTORE_NONE as u8 {
+        if fs.fh.lr.frame_restoration_type[plane] == RESTORE_NONE as u8 {
             continue;
         }
-        let (sub_x, sub_y) = if plane > 0 { (fs.ssx as i32, fs.ssy as i32) } else { (0, 0) };
-        let unit_size = fh.lr.loop_restoration_size[plane] as i32;
-        let unit_rows = fs.lr_unit_rows[plane] as i32;
-        let unit_cols = fs.lr_unit_cols[plane] as i32;
-        let plane_end_x = ((up_w + sub_x) >> sub_x) - 1;
-        let plane_end_y = ((fr_h + sub_y) >> sub_y) - 1;
-        let mut row = 0;
-        while row * 4 < fr_h {
-            let luma_y = row * 4;
-            let stripe_num = (luma_y + 8) / 64;
-            let stripe_start_y = (-8 + stripe_num * 64) >> sub_y;
-            let stripe_end_y = stripe_start_y + (64 >> sub_y) - 1;
-            let ctx = LrCtx { cur: &cur.planes[plane], cdef: &cdef.planes[plane], plane_end_x, plane_end_y, stripe_start_y, stripe_end_y };
-            let unit_row = (unit_rows - 1).min(((row * 4 + 8) >> sub_y) / unit_size);
-            let mut col = 0;
-            while col * 4 < up_w {
-                let unit_col = (unit_cols - 1).min(((col * 4) >> sub_x) / unit_size);
-                let x = (col * 4) >> sub_x;
-                let y = (row * 4) >> sub_y;
-                let w = (4 >> sub_x).min(plane_end_x - x + 1);
-                let h = (4 >> sub_y).min(plane_end_y - y + 1);
-                if w > 0 && h > 0 {
-                    let ui = (unit_row * unit_cols + unit_col) as usize;
-                    match fs.lr.lr_type[plane][ui] {
-                        t if t == RESTORE_WIENER as u8 => wiener(fs, &ctx, &mut lr.planes[plane], plane, ui, x, y, w, h, bd),
-                        t if t == RESTORE_SGRPROJ as u8 => self_guided(fs, &ctx, &mut lr.planes[plane], plane, ui, x, y, w, h, bd),
-                        _ => {}
-                    }
-                }
-                col += 1;
-            }
-            row += 1;
-        }
+        restore_plane(fs, cur, cdef, &mut lr.planes[plane], plane);
     }
     lr
 }
 
-#[allow(clippy::too_many_arguments)]
-fn wiener(fs: &FrameState, ctx: &LrCtx, out: &mut Plane, plane: usize, ui: usize, x: i32, y: i32, w: i32, h: i32, bd: u32) {
+fn restore_plane(fs: &FrameState, cur: &FrameBuf, cdef: &FrameBuf, out: &mut Plane, plane: usize) {
+    let fh = &fs.fh;
+    let up_w = fh.upscaled_width as i32;
+    let fr_h = fh.frame_height as i32;
+    let bd = fs.bit_depth;
+    let (sub_x, sub_y) = if plane > 0 { (fs.ssx as i32, fs.ssy as i32) } else { (0, 0) };
+    let unit_size = fh.lr.loop_restoration_size[plane] as i32;
+    let unit_rows = fs.lr_unit_rows[plane] as i32;
+    let unit_cols = fs.lr_unit_cols[plane] as i32;
+    let plane_end_x = ((up_w + sub_x) >> sub_x) - 1;
+    let plane_end_y = ((fr_h + sub_y) >> sub_y) - 1;
+    let mut row = 0;
+    while row * 4 < fr_h {
+        let luma_y = row * 4;
+        let stripe_num = (luma_y + 8) / 64;
+        let stripe_start_y = (-8 + stripe_num * 64) >> sub_y;
+        let stripe_end_y = stripe_start_y + (64 >> sub_y) - 1;
+        let ctx = LrCtx { cur: &cur.planes[plane], cdef: &cdef.planes[plane], plane_end_x, plane_end_y, stripe_start_y, stripe_end_y };
+        let unit_row = (unit_rows - 1).min(((row * 4 + 8) >> sub_y) / unit_size);
+        let mut col = 0;
+        while col * 4 < up_w {
+            let unit_col = (unit_cols - 1).min(((col * 4) >> sub_x) / unit_size);
+            let x = (col * 4) >> sub_x;
+            let y = (row * 4) >> sub_y;
+            let w = (4 >> sub_x).min(plane_end_x - x + 1);
+            let h = (4 >> sub_y).min(plane_end_y - y + 1);
+            if w > 0 && h > 0 {
+                let ui = (unit_row * unit_cols + unit_col) as usize;
+                let blk = LrBlock { x, y, w, h };
+                match fs.lr.lr_type[plane][ui] {
+                    t if t == RESTORE_WIENER as u8 => wiener(fs, &ctx, out, (plane, ui), blk, bd),
+                    t if t == RESTORE_SGRPROJ as u8 => self_guided(fs, &ctx, out, (plane, ui), blk, bd),
+                    _ => {}
+                }
+            }
+            col += 1;
+        }
+        row += 1;
+    }
+}
+
+fn wiener(fs: &FrameState, ctx: &LrCtx, out: &mut Plane, (plane, ui): (usize, usize), blk: LrBlock, bd: u32) {
+    let LrBlock { x, y, w, h } = blk;
     let round0: u32 = if bd == 12 { 5 } else { 3 };
     let round1: u32 = if bd == 12 { 9 } else { 11 };
     let coef = &fs.lr.lr_wiener[plane][ui];
@@ -166,13 +179,13 @@ fn wiener(fs: &FrameState, ctx: &LrCtx, out: &mut Plane, plane: usize, ui: usize
     }
 }
 
-#[allow(clippy::too_many_arguments)]
-fn self_guided(fs: &FrameState, ctx: &LrCtx, out: &mut Plane, plane: usize, ui: usize, x: i32, y: i32, w: i32, h: i32, bd: u32) {
+fn self_guided(fs: &FrameState, ctx: &LrCtx, out: &mut Plane, (plane, ui): (usize, usize), blk: LrBlock, bd: u32) {
+    let LrBlock { x, y, w, h } = blk;
     let set = fs.lr.lr_sgr_set[plane][ui] as usize;
     let mut flt0 = [[0i32; 4]; 4];
     let mut flt1 = [[0i32; 4]; 4];
-    box_filter(ctx, x, y, w, h, set, 0, bd, &mut flt0);
-    box_filter(ctx, x, y, w, h, set, 1, bd, &mut flt1);
+    box_filter(ctx, blk, (set, 0), bd, &mut flt0);
+    box_filter(ctx, blk, (set, 1), bd, &mut flt1);
     let xqd = fs.lr.lr_sgr_xqd[plane][ui];
     let w0 = xqd[0] as i32;
     let w1 = xqd[1] as i32;
@@ -198,8 +211,56 @@ fn round2_64(x: i64, n: u32) -> i64 {
     if n == 0 { x } else { (x + (1i64 << (n - 1))) >> n }
 }
 
-#[allow(clippy::too_many_arguments)]
-fn box_filter(ctx: &LrCtx, x: i32, y: i32, w: i32, h: i32, set: usize, pass: usize, bd: u32, f: &mut [[i32; 4]; 4]) {
+/// Box sums of the samples within `r` of (x, y): (sum of squares, sum).
+fn box_sums(ctx: &LrCtx, x: i32, y: i32, r: i32) -> (i64, i64) {
+    let mut a = 0i64;
+    let mut b = 0i64;
+    for dy in -r..=r {
+        for dx in -r..=r {
+            let c = ctx.sample(x + dx, y + dy) as i64;
+            a += c * c;
+            b += c;
+        }
+    }
+    (a, b)
+}
+
+/// Self-guided filter constants of one pass.
+struct SgrConsts {
+    n: i64,
+    s: i64,
+    one_over_n: i64,
+}
+
+/// (A, B) coefficients of one sample from its box sums.
+fn sgr_coefficients(a: i64, b: i64, k: &SgrConsts, bd: u32) -> (i64, i64) {
+    let a = round2_64(a, 2 * (bd - 8));
+    let d = round2_64(b, bd - 8);
+    let p = (a * k.n - d * d).max(0);
+    let z = round2_64(p * k.s, SGRPROJ_MTABLE_BITS as u32);
+    let a2 = if z >= 255 {
+        256
+    } else if z == 0 {
+        1
+    } else {
+        ((z << SGRPROJ_SGR_BITS) + z / 2) / (z + 1)
+    };
+    let b2 = ((1i64 << SGRPROJ_SGR_BITS) - a2) * b * k.one_over_n;
+    (a2, round2_64(b2, SGRPROJ_RECIP_BITS as u32))
+}
+
+fn box_weight(pass: usize, i: i32, dx: i32, dy: i32) -> i64 {
+    if pass == 0 {
+        if ((i + dy) & 1) != 0 { if dx == 0 { 6 } else { 5 } } else { 0 }
+    } else if dx == 0 || dy == 0 {
+        4
+    } else {
+        3
+    }
+}
+
+fn box_filter(ctx: &LrCtx, blk: LrBlock, (set, pass): (usize, usize), bd: u32, f: &mut [[i32; 4]; 4]) {
+    let LrBlock { x, y, w, h } = blk;
     let r = SGR_PARAMS[set][pass * 2] as i32;
     if r == 0 {
         return;
@@ -207,35 +268,15 @@ fn box_filter(ctx: &LrCtx, x: i32, y: i32, w: i32, h: i32, set: usize, pass: usi
     let eps = SGR_PARAMS[set][pass * 2 + 1] as i64;
     let n = ((2 * r + 1) * (2 * r + 1)) as i64;
     let n2e = n * n * eps;
-    let s = ((1i64 << SGRPROJ_MTABLE_BITS) + n2e / 2) / n2e;
-    let one_over_n = ((1i64 << SGRPROJ_RECIP_BITS) + n / 2) / n;
+    let k = SgrConsts { n, s: ((1i64 << SGRPROJ_MTABLE_BITS) + n2e / 2) / n2e, one_over_n: ((1i64 << SGRPROJ_RECIP_BITS) + n / 2) / n };
     let mut a_arr = [[0i64; 6]; 6];
     let mut b_arr = [[0i64; 6]; 6];
     for i in -1..h + 1 {
         for j in -1..w + 1 {
-            let mut a = 0i64;
-            let mut b = 0i64;
-            for dy in -r..=r {
-                for dx in -r..=r {
-                    let c = ctx.sample(x + j + dx, y + i + dy) as i64;
-                    a += c * c;
-                    b += c;
-                }
-            }
-            let a = round2_64(a, 2 * (bd - 8));
-            let d = round2_64(b, bd - 8);
-            let p = (a * n - d * d).max(0);
-            let z = round2_64(p * s, SGRPROJ_MTABLE_BITS as u32);
-            let a2 = if z >= 255 {
-                256
-            } else if z == 0 {
-                1
-            } else {
-                ((z << SGRPROJ_SGR_BITS) + z / 2) / (z + 1)
-            };
-            let b2 = ((1i64 << SGRPROJ_SGR_BITS) - a2) * b * one_over_n;
+            let (a, b) = box_sums(ctx, x + j, y + i, r);
+            let (a2, b2) = sgr_coefficients(a, b, &k, bd);
             a_arr[(i + 1) as usize][(j + 1) as usize] = a2;
-            b_arr[(i + 1) as usize][(j + 1) as usize] = round2_64(b2, SGRPROJ_RECIP_BITS as u32);
+            b_arr[(i + 1) as usize][(j + 1) as usize] = b2;
         }
     }
     for i in 0..h {
@@ -245,13 +286,7 @@ fn box_filter(ctx: &LrCtx, x: i32, y: i32, w: i32, h: i32, set: usize, pass: usi
             let mut b = 0i64;
             for dy in -1..=1i32 {
                 for dx in -1..=1i32 {
-                    let weight = if pass == 0 {
-                        if ((i + dy) & 1) != 0 { if dx == 0 { 6 } else { 5 } } else { 0 }
-                    } else if dx == 0 || dy == 0 {
-                        4
-                    } else {
-                        3
-                    };
+                    let weight = box_weight(pass, i, dx, dy);
                     a += weight * a_arr[(i + dy + 1) as usize][(j + dx + 1) as usize];
                     b += weight * b_arr[(i + dy + 1) as usize][(j + dx + 1) as usize];
                 }

crates/av1/src/transform.rs

@@ -165,6 +165,15 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
     for i in 0..len {
         t[i] = copy[brev(n, i)];
     }
+    inverse_dct_stage1(t, n, r);
+    inverse_dct_stage2(t, n, r);
+    inverse_dct_stage3(t, n, r);
+    inverse_dct_stage4(t, n, r);
+    inverse_dct_stage5(t, n, r);
+    inverse_dct_stage6(t, n, r);
+}
+
+fn inverse_dct_stage1<T: Lane>(t: &mut [T], n: u32, r: u32) {
     if n == 6 {
         for i in 0..16 {
             bf(t, 32 + i, 63 - i, 63 - 4 * brev(4, i) as i32, false);
@@ -190,6 +199,9 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
             hd(t, 16 + 2 * i, 17 + 2 * i, i & 1 == 1, r);
         }
     }
+}
+
+fn inverse_dct_stage2<T: Lane>(t: &mut [T], n: u32, r: u32) {
     if n == 6 {
         for i in 0..4 {
             for j in 0..2 {
@@ -221,6 +233,9 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
             }
         }
     }
+}
+
+fn inverse_dct_stage3<T: Lane>(t: &mut [T], n: u32, r: u32) {
     for i in 0..2 {
         bf(t, 2 * i, 2 * i + 1, 32 + 16 * i as i32, i == 0);
     }
@@ -248,6 +263,9 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
             }
         }
     }
+}
+
+fn inverse_dct_stage4<T: Lane>(t: &mut [T], n: u32, r: u32) {
     for i in 0..2 {
         hd(t, i, 3 - i, false, r);
     }
@@ -273,6 +291,9 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
             }
         }
     }
+}
+
+fn inverse_dct_stage5<T: Lane>(t: &mut [T], n: u32, r: u32) {
     if n >= 3 {
         for i in 0..4 {
             hd(t, i, 7 - i, false, r);
@@ -300,6 +321,9 @@ pub(crate) fn inverse_dct<T: Lane>(t: &mut [T], n: u32, r: u32) {
             hd(t, i, 15 - i, false, r);
         }
     }
+}
+
+fn inverse_dct_stage6<T: Lane>(t: &mut [T], n: u32, r: u32) {
     if n >= 5 {
         for i in 0..4 {
             bf(t, 27 - i, 20 + i, 32, true);
@@ -531,10 +555,9 @@ pub(crate) fn inverse_transform_2d(dequant: &[i32], residual: &mut [i32], tx_sz:
     let col_clamp = (bit_depth + 6).max(16);
     let rk = row_kind(tx_type);
     let ck = col_kind(tx_type);
-    let mut t = [0i32; 64];
     let rect2 = log2w.abs_diff(log2h) == 1;
+    let p = Tx2d { w, h, log2w, log2h, row_shift, col_shift, row_clamp, col_clamp, rk, ck, rect2 };
     if !lossless && bit_depth <= 10 {
-        let p = Tx2d { w, h, log2w, log2h, row_shift, col_shift, row_clamp, col_clamp, rk, ck, rect2 };
         if w >= 8 && h >= 8 {
             transform_lanes::<8>(dequant, residual, &p);
         } else {
@@ -542,6 +565,13 @@ pub(crate) fn inverse_transform_2d(dequant: &[i32], residual: &mut [i32], tx_sz:
         }
         return;
     }
+    scalar_row_pass(dequant, residual, &p, lossless);
+    scalar_col_pass(residual, &p, lossless);
+}
+
+fn scalar_row_pass(dequant: &[i32], residual: &mut [i32], p: &Tx2d, lossless: bool) {
+    let (w, h, log2w, row_shift, row_clamp, col_clamp, rk, rect2) = (p.w, p.h, p.log2w, p.row_shift, p.row_clamp, p.col_clamp, p.rk, p.rect2);
+    let mut t = [0i32; 64];
     let in_w = w.min(32);
     for i in 0..h {
         // Every 1D transform maps an all-zero row to zeros (each step is linear with
@@ -572,6 +602,11 @@ pub(crate) fn inverse_transform_2d(dequant: &[i32], residual: &mut [i32], tx_sz:
             residual[i * w + j] = round2(t[j], row_shift).clamp(lo, hi);
         }
     }
+}
+
+fn scalar_col_pass(residual: &mut [i32], p: &Tx2d, lossless: bool) {
+    let (w, h, log2h, col_shift, col_clamp, ck) = (p.w, p.h, p.log2h, p.col_shift, p.col_clamp, p.ck);
+    let mut t = [0i32; 64];
     for j in 0..w {
         for i in 0..h {
             t[i] = residual[i * w + j];
@@ -617,11 +652,16 @@ fn transform_1d<T: Lane>(t: &mut [T], kind: Kind1d, n: u32, r: u32) {
 /// The 2D inverse transform with `L` rows (row pass) or columns (column pass) at a time;
 /// bit-identical to the one-at-a-time process for bit depths up to 10.
 fn transform_lanes<const L: usize>(dequant: &[i32], residual: &mut [i32], p: &Tx2d) {
+    let mut t = [[0i32; L]; 64];
+    lanes_row_pass(dequant, residual, p, &mut t);
+    lanes_col_pass(residual, p, &mut t);
+}
+
+fn lanes_row_pass<const L: usize>(dequant: &[i32], residual: &mut [i32], p: &Tx2d, t: &mut [[i32; L]; 64]) {
     let (w, h) = (p.w, p.h);
     let in_w = w.min(32);
     let lo = -(1i32 << (p.col_clamp - 1));
     let hi = (1i32 << (p.col_clamp - 1)) - 1;
-    let mut t = [[0i32; L]; 64];
     let mut i0 = 0;
     while i0 < h {
         // Rows without coefficients (and rows 32..63) transform to zeros.
@@ -649,6 +689,10 @@ fn transform_lanes<const L: usize>(dequant: &[i32], residual: &mut [i32], p: &Tx
         }
         i0 += L;
     }
+}
+
+fn lanes_col_pass<const L: usize>(residual: &mut [i32], p: &Tx2d, t: &mut [[i32; L]; 64]) {
+    let (w, h) = (p.w, p.h);
     let mut j0 = 0;
     while j0 < w {
         for i in 0..h {

crates/h264/src/dpb.rs

@@ -3,7 +3,7 @@
 
 use crate::error::{Result, ensure};
 use crate::picture::{FrameRef, RefPic};
-use crate::slice::{Mmco, SliceHeader, SliceType};
+use crate::slice::{Mmco, RefPicListMod, SliceHeader, SliceType};
 use std::sync::Arc;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -174,6 +174,103 @@ impl Dpb {
         }
     }
 
+    /// Initial reference picture lists (8.2.4.2) as DPB entries.
+    fn initial_entry_lists<'a>(
+        sh: &SliceHeader,
+        cur_poc: i32,
+        short: &[&'a DpbEntry],
+        long: &[&'a DpbEntry],
+        pic_num: impl Fn(&DpbEntry) -> i32,
+    ) -> [Vec<&'a DpbEntry>; 2] {
+        let mut entry_lists: [Vec<&'a DpbEntry>; 2] = [Vec::new(), Vec::new()];
+        if sh.slice_type != SliceType::B {
+            let mut s = short.to_vec();
+            s.sort_by_key(|e| std::cmp::Reverse(pic_num(e)));
+            entry_lists[0] = s.into_iter().chain(long.iter().copied()).collect();
+        } else {
+            let mut before: Vec<&'a DpbEntry> = short.iter().copied().filter(|e| e.poc < cur_poc).collect();
+            let mut after: Vec<&'a DpbEntry> = short.iter().copied().filter(|e| e.poc > cur_poc).collect();
+            before.sort_by_key(|e| std::cmp::Reverse(e.poc));
+            after.sort_by_key(|e| e.poc);
+            entry_lists[0] = before.iter().chain(after.iter()).chain(long.iter()).copied().collect();
+            entry_lists[1] = after.iter().chain(before.iter()).chain(long.iter()).copied().collect();
+            if entry_lists[1].len() > 1 && entry_lists[0].len() == entry_lists[1].len() {
+                let same = entry_lists[0].iter().zip(entry_lists[1].iter()).all(|(a, b)| std::ptr::eq(*a, *b));
+                if same {
+                    entry_lists[1].swap(0, 1);
+                }
+            }
+        }
+        entry_lists
+    }
+
+    /// Reference picture list modification (8.2.4.3) of one list; `n` is num_ref_idx_active.
+    fn modify_ref_list<'a>(
+        list: &mut Vec<Option<&'a DpbEntry>>,
+        mods: &[RefPicListMod],
+        n: usize,
+        cur_fn: u32,
+        max_frame_num: u32,
+        short: &[&'a DpbEntry],
+        long: &[&'a DpbEntry],
+    ) -> Result<()> {
+        let max_pic_num = max_frame_num as i32;
+        let curr_pic_num = cur_fn as i32;
+        let mut pred = curr_pic_num;
+        let mut ref_idx = 0usize;
+        for m in mods {
+            ensure!(ref_idx < n, "too many ref_pic_list_modification entries");
+            list.push(None); // temporarily one longer
+            let (target, is_long): (Option<&DpbEntry>, bool) = match m.idc {
+                0 | 1 => {
+                    let d = m.value as i32 + 1;
+                    let no_wrap = if m.idc == 0 {
+                        if pred - d < 0 { pred - d + max_pic_num } else { pred - d }
+                    } else if pred + d >= max_pic_num {
+                        pred + d - max_pic_num
+                    } else {
+                        pred + d
+                    };
+                    pred = no_wrap;
+                    let pn = if no_wrap > curr_pic_num { no_wrap - max_pic_num } else { no_wrap };
+                    (short.iter().copied().find(|e| Self::frame_num_wrap(e, cur_fn, max_frame_num) == pn), false)
+                }
+                2 => (long.iter().copied().find(|e| e.long_term_frame_idx == m.value), true),
+                _ => continue,
+            };
+            let Some(target) = target else {
+                // Missing picture: keep the list unchanged (error concealment).
+                list.pop();
+                ref_idx += 1;
+                continue;
+            };
+            for c in (ref_idx + 1..=n).rev() {
+                list[c] = list[c - 1];
+            }
+            list[ref_idx] = Some(target);
+            ref_idx += 1;
+            let mut nidx = ref_idx;
+            for c in ref_idx..=n {
+                let keep = match list[c] {
+                    None => true,
+                    Some(e) => {
+                        if is_long {
+                            !(e.mark == RefMark::Long && e.long_term_frame_idx == target.long_term_frame_idx)
+                        } else {
+                            !(e.mark == RefMark::Short && std::ptr::eq(e, target))
+                        }
+                    }
+                };
+                if keep {
+                    list[nidx] = list[c];
+                    nidx += 1;
+                }
+            }
+            list.truncate(n);
+        }
+        Ok(())
+    }
+
     /// Initial reference picture lists (8.2.4.2) + modification (8.2.4.3) for a frame slice.
     pub fn build_ref_lists(&self, sh: &SliceHeader, cur_poc: i32, max_frame_num: u32) -> Result<[Vec<RefPic>; 2]> {
         let mut lists: [Vec<RefPic>; 2] = [Vec::new(), Vec::new()];
@@ -186,25 +283,7 @@ impl Dpb {
         let mut long: Vec<&DpbEntry> = self.entries.iter().filter(|e| e.mark == RefMark::Long).collect();
         long.sort_by_key(|e| e.long_term_frame_idx);
         let to_ref = |e: &&DpbEntry| RefPic { frame: e.frame.clone(), long_term: e.mark == RefMark::Long };
-        let mut entry_lists: [Vec<&DpbEntry>; 2] = [Vec::new(), Vec::new()];
-        if sh.slice_type != SliceType::B {
-            let mut s = short.clone();
-            s.sort_by_key(|e| std::cmp::Reverse(pic_num(e)));
-            entry_lists[0] = s.into_iter().chain(long.iter().copied()).collect();
-        } else {
-            let mut before: Vec<&DpbEntry> = short.iter().copied().filter(|e| e.poc < cur_poc).collect();
-            let mut after: Vec<&DpbEntry> = short.iter().copied().filter(|e| e.poc > cur_poc).collect();
-            before.sort_by_key(|e| std::cmp::Reverse(e.poc));
-            after.sort_by_key(|e| e.poc);
-            entry_lists[0] = before.iter().chain(after.iter()).chain(long.iter()).copied().collect();
-            entry_lists[1] = after.iter().chain(before.iter()).chain(long.iter()).copied().collect();
-            if entry_lists[1].len() > 1 && entry_lists[0].len() == entry_lists[1].len() {
-                let same = entry_lists[0].iter().zip(entry_lists[1].iter()).all(|(a, b)| std::ptr::eq(*a, *b));
-                if same {
-                    entry_lists[1].swap(0, 1);
-                }
-            }
-        }
+        let entry_lists = Self::initial_entry_lists(sh, cur_poc, &short, &long, pic_num);
         let nlists = if sh.slice_type == SliceType::B { 2 } else { 1 };
         for l in 0..nlists {
             let n = sh.num_ref_idx_active[l] as usize;
@@ -212,60 +291,7 @@ impl Dpb {
             list.truncate(n);
             list.resize(n, None);
             if !sh.ref_pic_list_mod[l].is_empty() {
-                let max_pic_num = max_frame_num as i32;
-                let curr_pic_num = cur_fn as i32;
-                let mut pred = curr_pic_num;
-                let mut ref_idx = 0usize;
-                for m in &sh.ref_pic_list_mod[l] {
-                    ensure!(ref_idx < n, "too many ref_pic_list_modification entries");
-                    list.push(None); // temporarily one longer
-                    let (target, is_long): (Option<&DpbEntry>, bool) = match m.idc {
-                        0 | 1 => {
-                            let d = m.value as i32 + 1;
-                            let no_wrap = if m.idc == 0 {
-                                if pred - d < 0 { pred - d + max_pic_num } else { pred - d }
-                            } else if pred + d >= max_pic_num {
-                                pred + d - max_pic_num
-                            } else {
-                                pred + d
-                            };
-                            pred = no_wrap;
-                            let pn = if no_wrap > curr_pic_num { no_wrap - max_pic_num } else { no_wrap };
-                            (short.iter().copied().find(|e| pic_num(e) == pn), false)
-                        }
-                        2 => (long.iter().copied().find(|e| e.long_term_frame_idx == m.value), true),
-                        _ => continue,
-                    };
-                    let Some(target) = target else {
-                        // Missing picture: keep the list unchanged (error concealment).
-                        list.pop();
-                        ref_idx += 1;
-                        continue;
-                    };
-                    for c in (ref_idx + 1..=n).rev() {
-                        list[c] = list[c - 1];
-                    }
-                    list[ref_idx] = Some(target);
-                    ref_idx += 1;
-                    let mut nidx = ref_idx;
-                    for c in ref_idx..=n {
-                        let keep = match list[c] {
-                            None => true,
-                            Some(e) => {
-                                if is_long {
-                                    !(e.mark == RefMark::Long && e.long_term_frame_idx == target.long_term_frame_idx)
-                                } else {
-                                    !(e.mark == RefMark::Short && std::ptr::eq(e, target))
-                                }
-                            }
-                        };
-                        if keep {
-                            list[nidx] = list[c];
-                            nidx += 1;
-                        }
-                    }
-                    list.truncate(n);
-                }
+                Self::modify_ref_list(&mut list, &sh.ref_pic_list_mod[l], n, cur_fn, max_frame_num, &short, &long)?;
             }
             // Fill missing entries (should not happen in conforming streams) with the first valid entry.
             let fallback = list.iter().flatten().next().copied().or_else(|| self.entries.last());
@@ -275,91 +301,88 @@ impl Dpb {
         Ok(lists)
     }
 
-    /// Adaptive memory control (8.2.5.4). Returns true if MMCO 5 was executed.
-    fn apply_mmcos(&mut self, mmcos: &[Mmco], cur_frame_num: u32, max_frame_num: u32, cur_long: &mut Option<u32>) -> bool {
+    /// One memory management control operation; returns true for MMCO 5.
+    fn apply_mmco(&mut self, m: &Mmco, cur_frame_num: u32, max_frame_num: u32, cur_long: &mut Option<u32>) -> bool {
         let mut had5 = false;
         let curr_pic_num = cur_frame_num as i32;
-        for m in mmcos {
-            match m.op {
-                1 => {
-                    let pn = curr_pic_num - (m.difference_of_pic_nums_minus1 as i32 + 1);
-                    for e in &mut self.entries {
-                        if e.mark == RefMark::Short && Self::frame_num_wrap(e, cur_frame_num, max_frame_num) == pn {
-                            e.mark = RefMark::Unused;
-                        }
+        match m.op {
+            1 => {
+                let pn = curr_pic_num - (m.difference_of_pic_nums_minus1 as i32 + 1);
+                for e in &mut self.entries {
+                    if e.mark == RefMark::Short && Self::frame_num_wrap(e, cur_frame_num, max_frame_num) == pn {
+                        e.mark = RefMark::Unused;
                     }
                 }
-                2 => {
-                    for e in &mut self.entries {
-                        if e.mark == RefMark::Long && e.long_term_frame_idx == m.long_term_pic_num {
-                            e.mark = RefMark::Unused;
-                        }
+            }
+            2 => {
+                for e in &mut self.entries {
+                    if e.mark == RefMark::Long && e.long_term_frame_idx == m.long_term_pic_num {
+                        e.mark = RefMark::Unused;
                     }
                 }
-                3 => {
-                    let pn = curr_pic_num - (m.difference_of_pic_nums_minus1 as i32 + 1);
+            }
+            3 => {
+                let pn = curr_pic_num - (m.difference_of_pic_nums_minus1 as i32 + 1);
+                for e in &mut self.entries {
+                    if e.mark == RefMark::Long && e.long_term_frame_idx == m.long_term_frame_idx {
+                        e.mark = RefMark::Unused;
+                    }
+                }
+                for e in &mut self.entries {
+                    if e.mark == RefMark::Short && Self::frame_num_wrap(e, cur_frame_num, max_frame_num) == pn {
+                        e.mark = RefMark::Long;
+                        e.long_term_frame_idx = m.long_term_frame_idx;
+                    }
+                }
+            }
+            4 => {
+                let max = m.max_long_term_frame_idx_plus1;
+                for e in &mut self.entries {
+                    if e.mark == RefMark::Long && (max == 0 || e.long_term_frame_idx > max - 1) {
+                        e.mark = RefMark::Unused;
+                    }
+                }
+                self.max_long_term_frame_idx = if max == 0 { None } else { Some(max - 1) };
+            }
+            5 => {
+                for e in &mut self.entries {
+                    e.mark = RefMark::Unused;
+                }
+                self.max_long_term_frame_idx = None;
+                had5 = true;
+            }
+            6 => {
+                // Only an index within the allowed range may be assigned (8.2.5.4.6).
+                let allowed = match self.max_long_term_frame_idx {
+                    Some(max) => m.long_term_frame_idx <= max,
+                    None => false,
+                };
+                if allowed {
                     for e in &mut self.entries {
                         if e.mark == RefMark::Long && e.long_term_frame_idx == m.long_term_frame_idx {
                             e.mark = RefMark::Unused;
                         }
                     }
-                    for e in &mut self.entries {
-                        if e.mark == RefMark::Short && Self::frame_num_wrap(e, cur_frame_num, max_frame_num) == pn {
-                            e.mark = RefMark::Long;
-                            e.long_term_frame_idx = m.long_term_frame_idx;
-                        }
-                    }
+                    *cur_long = Some(m.long_term_frame_idx);
                 }
-                4 => {
-                    let max = m.max_long_term_frame_idx_plus1;
-                    for e in &mut self.entries {
-                        if e.mark == RefMark::Long && (max == 0 || e.long_term_frame_idx > max - 1) {
-                            e.mark = RefMark::Unused;
-                        }
-                    }
-                    self.max_long_term_frame_idx = if max == 0 { None } else { Some(max - 1) };
-                }
-                5 => {
-                    for e in &mut self.entries {
-                        e.mark = RefMark::Unused;
-                    }
-                    self.max_long_term_frame_idx = None;
-                    had5 = true;
-                }
-                6 => {
-                    let allowed = match self.max_long_term_frame_idx {
-                        Some(max) => m.long_term_frame_idx <= max,
-                        None => false,
-                    };
-                    if allowed {
-                        for e in &mut self.entries {
-                            if e.mark == RefMark::Long && e.long_term_frame_idx == m.long_term_frame_idx {
-                                e.mark = RefMark::Unused;
-                            }
-                        }
-                        *cur_long = Some(m.long_term_frame_idx);
-                    }
-                }
-                _ => {}
             }
+            _ => {}
+        }
+        had5
+    }
+
+    /// Adaptive memory control (8.2.5.4). Returns true if MMCO 5 was executed.
+    fn apply_mmcos(&mut self, mmcos: &[Mmco], cur_frame_num: u32, max_frame_num: u32, cur_long: &mut Option<u32>) -> bool {
+        let mut had5 = false;
+        for m in mmcos {
+            had5 |= self.apply_mmco(m, cur_frame_num, max_frame_num, cur_long);
         }
         self.prune();
         had5
     }
 
-    /// Reference marking for the just-decoded picture and insertion into the DPB with output bumping.
-    /// Returns pictures ready for output.
-    #[allow(clippy::too_many_arguments)]
-    pub fn store_picture(
-        &mut self,
-        sh: &SliceHeader,
-        frame: FrameRef,
-        poc: i32,
-        max_frame_num: u32,
-        max_num_ref_frames: usize,
-        meta: Arc<OutputMeta>,
-        out: &mut Vec<Output>,
-    ) {
+    /// Reference marking of the current picture (8.2.5); returns (mark, long-term idx, MMCO 5 executed).
+    fn mark_current(&mut self, sh: &SliceHeader, max_frame_num: u32, max_num_ref_frames: usize) -> (RefMark, u32, bool) {
         let mut mark = RefMark::Unused;
         let mut long_idx = 0;
         let mut had5 = false;
@@ -391,12 +414,12 @@ impl Dpb {
                 }
             }
         }
-        if had5 {
-            // All earlier pictures are output before the current one (C.4.4).
-            self.flush(out);
-        }
-        let frame_num = if had5 { 0 } else { sh.frame_num };
-        // Bumping until there is space (C.4.5.1 / C.4.5.2).
+        (mark, long_idx, had5)
+    }
+
+    /// Bumping until there is space (C.4.5.1 / C.4.5.2). Returns true when the (non-reference) current
+    /// picture has the smallest POC and is to be output directly instead of being stored.
+    fn bump_for_space(&mut self, mark: RefMark, poc: i32, out: &mut Vec<Output>) -> bool {
         if mark == RefMark::Unused {
             loop {
                 let waiting = self.entries.len();
@@ -406,8 +429,7 @@ impl Dpb {
                 // non-reference picture with the smallest POC is output directly
                 let min_poc = self.entries.iter().filter(|e| e.needed_for_output).map(|e| e.poc).min();
                 if min_poc.is_none_or(|m| poc < m) {
-                    out.push(Output { frame, poc, meta });
-                    return;
+                    return true;
                 }
                 if !self.bump(out) {
                     break;
@@ -425,6 +447,32 @@ impl Dpb {
                 }
             }
         }
+        false
+    }
+
+    /// Reference marking for the just-decoded picture and insertion into the DPB with output bumping.
+    /// Returns pictures ready for output.
+    #[allow(clippy::too_many_arguments)]
+    pub fn store_picture(
+        &mut self,
+        sh: &SliceHeader,
+        frame: FrameRef,
+        poc: i32,
+        max_frame_num: u32,
+        max_num_ref_frames: usize,
+        meta: Arc<OutputMeta>,
+        out: &mut Vec<Output>,
+    ) {
+        let (mark, long_idx, had5) = self.mark_current(sh, max_frame_num, max_num_ref_frames);
+        if had5 {
+            // All earlier pictures are output before the current one (C.4.4).
+            self.flush(out);
+        }
+        let frame_num = if had5 { 0 } else { sh.frame_num };
+        if self.bump_for_space(mark, poc, out) {
+            out.push(Output { frame, poc, meta });
+            return;
+        }
         self.entries.push(DpbEntry {
             frame,
             poc,

crates/h264/src/params.rs

@@ -575,7 +575,7 @@ impl Pps {
         ensure!(sps_id < 32, "seq_parameter_set_id out of range");
         let sps = spss
             .get(sps_id as usize)
-            .and_then(|s| s.as_ref())
+            .and_then(Option::as_ref)
             .ok_or_else(|| crate::Error::MissingParameterSet(format!("SPS {sps_id} for PPS {id}")))?;
         let entropy_coding_mode = r.read_flag()?;
         let bottom_field_pic_order_in_frame_present = r.read_flag()?;

crates/h264/src/picture.rs

@@ -250,7 +250,7 @@ impl Frame {
 
     /// Copy the w x h window of chroma component `c` at (x0, y0) (clamped) into `out`.
     #[inline]
-    pub fn chroma_window(&self, c: usize, x0: i32, y0: i32, w: usize, h: usize, out: &mut [u8], os: usize) {
+    pub fn chroma_window(&self, c: usize, (x0, y0): (i32, i32), (w, h): (usize, usize), out: &mut [u8], os: usize) {
         let (cw, ch) = (self.cwidth, self.cheight);
         for r in 0..h {
             let yy = (y0 + r as i32).clamp(0, ch as i32 - 1) as usize;

crates/h264/src/slicedec.rs

@@ -232,7 +232,7 @@ fn predict_block(f: &Frame, mv: [i16; 2], px: usize, py: usize, bw: usize, bh: u
     let (fx, fy) = ((mv[0] & 7) as u32, (mv[1] & 7) as u32);
     for (comp, out) in c.into_iter().enumerate() {
         let mut w = [0u8; 16 * 9];
-        f.chroma_window(comp, cx, cy, cw + 1, ch + 1, &mut w, 16);
+        f.chroma_window(comp, (cx, cy), (cw + 1, ch + 1), &mut w, 16);
         inter::mc_chroma_win(&w, 16, fx, fy, cw, ch, out, cs);
     }
 }
@@ -665,33 +665,38 @@ impl<'a> SliceDecoder<'a> {
             return Ok(());
         }
         for p in 0..4 {
-            let sub = self.cur.sub[p];
-            let (x8, y8) = ((p & 1) * 2, (p >> 1) * 2);
-            if sub.direct {
-                self.derive_direct(1 << p)?;
-                continue;
+            self.derive_sub_mb_motion(p, n)?;
+        }
+        Ok(())
+    }
+
+    /// Motion of one 8x8 sub-macroblock `p` of a P8x8/B8x8 MB.
+    fn derive_sub_mb_motion(&mut self, p: usize, n: [usize; 2]) -> Result<()> {
+        let sub = self.cur.sub[p];
+        let (x8, y8) = ((p & 1) * 2, (p >> 1) * 2);
+        if sub.direct {
+            return self.derive_direct(1 << p);
+        }
+        let mut refs = [-1i8; 2];
+        for (l, r) in refs.iter_mut().enumerate() {
+            if sub.pred & (1 << l) != 0 {
+                let v = self.cur.ref_idx[l][p];
+                ensure!((v as usize) < n[l], "ref_idx {v} out of range (list {l}, size {})", n[l]);
+                *r = v;
             }
-            let mut refs = [-1i8; 2];
-            for (l, r) in refs.iter_mut().enumerate() {
-                if sub.pred & (1 << l) != 0 {
-                    let v = self.cur.ref_idx[l][p];
-                    ensure!((v as usize) < n[l], "ref_idx {v} out of range (list {l}, size {})", n[l]);
-                    *r = v;
+        }
+        for j in 0..sub.shape.num_parts() {
+            let (sx, sy, w, h) = sub.shape.rect(j);
+            let (x, y) = (x8 + sx, y8 + sy);
+            let mut mvs = [[0i16; 2]; 2];
+            for l in 0..2 {
+                if refs[l] >= 0 {
+                    let mvp = self.mvp(l, x, y, w, refs[l], 0, 0);
+                    let d = self.cur.mvd[l][p * 4 + j];
+                    mvs[l] = [mvp[0].wrapping_add(d[0]), mvp[1].wrapping_add(d[1])];
                 }
             }
-            for j in 0..sub.shape.num_parts() {
-                let (sx, sy, w, h) = sub.shape.rect(j);
-                let (x, y) = (x8 + sx, y8 + sy);
-                let mut mvs = [[0i16; 2]; 2];
-                for l in 0..2 {
-                    if refs[l] >= 0 {
-                        let mvp = self.mvp(l, x, y, w, refs[l], 0, 0);
-                        let d = self.cur.mvd[l][p * 4 + j];
-                        mvs[l] = [mvp[0].wrapping_add(d[0]), mvp[1].wrapping_add(d[1])];
-                    }
-                }
-                self.set_motion(x, y, w, h, refs, mvs);
-            }
+            self.set_motion(x, y, w, h, refs, mvs);
         }
         Ok(())
     }
@@ -1380,6 +1385,11 @@ impl<'a> SliceDecoder<'a> {
             cavlc::residual_block(r, &mut lv, 0, 15, 16, nc)?;
             self.put_luma_dc(&lv);
         }
+        self.residual_cavlc_luma(r, cbp, kind, t8)?;
+        self.residual_cavlc_chroma(r, cbp)
+    }
+
+    fn residual_cavlc_luma(&mut self, r: &mut BitReader, cbp: u8, kind: MbKind, t8: bool) -> Result<()> {
         for b8 in 0..4 {
             let (bx8, by8) = ((b8 & 1) * 2, (b8 >> 1) * 2);
             if cbp & (1 << b8) == 0 {
@@ -1413,6 +1423,10 @@ impl<'a> SliceDecoder<'a> {
                 }
             }
         }
+        Ok(())
+    }
+
+    fn residual_cavlc_chroma(&mut self, r: &mut BitReader, cbp: u8) -> Result<()> {
         let cbp_c = cbp >> 4;
         if cbp_c & 3 != 0 {
             for c in 0..2 {

crates/hevc/src/inter.rs

@@ -128,7 +128,7 @@ pub fn mc_chroma(f: &Frame, c: usize, x: i32, y: i32, mv: [i16; 2], w: usize, h:
     let yi = y + (mv[1] as i32 >> 3);
     let shift1 = bd.min(12) - 8;
     let shift3 = 14 - bd;
-    f.chroma_window(c, xi - 1, yi - 1, w + 3, h + 3, &mut sc.win, WIN);
+    f.chroma_window(c, (xi - 1, yi - 1), (w + 3, h + 3), &mut sc.win, WIN);
     interpolate::<4>(&sc.win, &mut sc.tmp, fx, fy, &CHROMA_FILTER[fx], &CHROMA_FILTER[fy], w, h, shift1, shift3, out);
 }
 
@@ -158,7 +158,7 @@ pub fn put_bi(p0: &[i16], p1: &[i16], w: usize, h: usize, bd: u32, dst: &mut [u1
 }
 
 /// Explicit weighted prediction, one list (8-265). `o` is the offset already scaled to the bit depth.
-pub fn put_weighted_uni(p: &[i16], w: usize, h: usize, bd: u32, log2wd: u32, wt: i32, o: i32, dst: &mut [u16], ds: usize) {
+pub fn put_weighted_uni(p: &[i16], (w, h): (usize, usize), bd: u32, (log2wd, wt, o): (u32, i32, i32), dst: &mut [u16], ds: usize) {
     let max = (1i32 << bd) - 1;
     for r in 0..h {
         for c in 0..w {
@@ -173,14 +173,9 @@ pub fn put_weighted_uni(p: &[i16], w: usize, h: usize, bd: u32, log2wd: u32, wt:
 pub fn put_weighted_bi(
     p0: &[i16],
     p1: &[i16],
-    w: usize,
-    h: usize,
+    (w, h): (usize, usize),
     bd: u32,
-    log2wd: u32,
-    w0: i32,
-    w1: i32,
-    o0: i32,
-    o1: i32,
+    (log2wd, w0, w1, o0, o1): (u32, i32, i32, i32, i32),
     dst: &mut [u16],
     ds: usize,
 ) {

crates/hevc/src/mvpred.rs

@@ -36,9 +36,23 @@ fn same_motion(a: &MvField, b: &MvField) -> bool {
     true
 }
 
+/// Coding block and prediction block geometry (6.4.2): coding block (xc, yc, ncb), prediction block (xp, yp, w, h, part_idx).
+#[derive(Clone, Copy)]
+pub struct PbGeom {
+    pub xc: i32,
+    pub yc: i32,
+    pub ncb: i32,
+    pub xp: i32,
+    pub yp: i32,
+    pub w: i32,
+    pub h: i32,
+    pub part_idx: usize,
+}
+
 impl<'a> SliceDecoder<'a> {
     /// Prediction block availability (6.4.2).
-    fn pb_avail(&self, xc: i32, yc: i32, ncb: i32, xp: i32, yp: i32, w: i32, h: i32, part_idx: usize, xn: i32, yn: i32) -> bool {
+    fn pb_avail(&self, g: &PbGeom, xn: i32, yn: i32) -> bool {
+        let PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx } = *g;
         let same_cb = xc <= xn && yc <= yn && xc + ncb > xn && yc + ncb > yn;
         let avail = if !same_cb {
             self.pic.zavail(xp, yp, xn, yn, self.slice_addr)
@@ -59,23 +73,13 @@ impl<'a> SliceDecoder<'a> {
     }
 
     /// Merge mode motion (8.5.3.2.2).
-    pub fn derive_merge(
-        &self,
-        xc: i32,
-        yc: i32,
-        ncb: i32,
-        xp0: i32,
-        yp0: i32,
-        w0: i32,
-        h0: i32,
-        part_idx0: usize,
-        part: PartMode,
-        merge_idx: usize,
-    ) -> MvField {
+    pub fn derive_merge(&self, g: PbGeom, part: PartMode, merge_idx: usize) -> MvField {
+        let PbGeom { xc, yc, ncb, xp: xp0, yp: yp0, w: w0, h: h0, part_idx: part_idx0 } = g;
         let pml = self.pps.log2_parallel_merge_level;
         let (xp, yp, w, h, part_idx) = if pml > 2 && ncb == 8 { (xc, yc, ncb, ncb, 0) } else { (xp0, yp0, w0, h0, part_idx0) };
+        let g = PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx };
         let same_mer = |xn: i32, yn: i32| (xp >> pml) == (xn >> pml) && (yp >> pml) == (yn >> pml);
-        let avail = |xn: i32, yn: i32| self.pb_avail(xc, yc, ncb, xp, yp, w, h, part_idx, xn, yn) && !same_mer(xn, yn);
+        let avail = |xn: i32, yn: i32| self.pb_avail(&g, xn, yn) && !same_mer(xn, yn);
         let mut list: [MvField; 5] = [MvField::default(); 5];
         let mut n = 0;
         let max = self.sh.max_num_merge_cand as usize;
@@ -237,20 +241,8 @@ impl<'a> SliceDecoder<'a> {
     }
 
     /// AMVP predictor (8.5.3.2.6, 8.5.3.2.7).
-    pub fn derive_amvp(
-        &self,
-        xc: i32,
-        yc: i32,
-        ncb: i32,
-        xp: i32,
-        yp: i32,
-        w: i32,
-        h: i32,
-        part_idx: usize,
-        l: usize,
-        ref_idx: usize,
-        mvp_flag: usize,
-    ) -> [i16; 2] {
+    pub fn derive_amvp(&self, g: PbGeom, l: usize, ref_idx: usize, mvp_flag: usize) -> [i16; 2] {
+        let PbGeom { xp, yp, w, h, .. } = g;
         let target = &self.refs[l][ref_idx];
         let (tpoc, tlt) = (target.poc, target.long_term);
         let cur_poc = self.pic.poc;
@@ -277,10 +269,7 @@ impl<'a> SliceDecoder<'a> {
             pick.map(|(mv, r)| if r.poc != tpoc && !r.long_term && !tlt { scale_mv(mv, cur_poc - r.poc, cur_poc - tpoc) } else { mv })
         };
         let pa = [(xp - 1, yp + h), (xp - 1, yp + h - 1)];
-        let av_a = [
-            self.pb_avail(xc, yc, ncb, xp, yp, w, h, part_idx, pa[0].0, pa[0].1),
-            self.pb_avail(xc, yc, ncb, xp, yp, w, h, part_idx, pa[1].0, pa[1].1),
-        ];
+        let av_a = [self.pb_avail(&g, pa[0].0, pa[0].1), self.pb_avail(&g, pa[1].0, pa[1].1)];
         let is_scaled = av_a[0] || av_a[1];
         let mut a = None;
         for k in 0..2 {
@@ -296,7 +285,7 @@ impl<'a> SliceDecoder<'a> {
             }
         }
         let pb = [(xp + w, yp - 1), (xp + w - 1, yp - 1), (xp - 1, yp - 1)];
-        let av_b = [0, 1, 2].map(|k| self.pb_avail(xc, yc, ncb, xp, yp, w, h, part_idx, pb[k].0, pb[k].1));
+        let av_b = [0, 1, 2].map(|k| self.pb_avail(&g, pb[k].0, pb[k].1));
         let mut b = None;
         for k in 0..3 {
             if av_b[k] && b.is_none() {

crates/hevc/src/picture.rs

@@ -125,7 +125,7 @@ impl Frame {
     }
 
     /// Copy a w x h window of chroma component `c` (0 = Cb, 1 = Cr) with edge replication.
-    pub fn chroma_window(&self, c: usize, x0: i32, y0: i32, w: usize, h: usize, out: &mut [i16], os: usize) {
+    pub fn chroma_window(&self, c: usize, (x0, y0): (i32, i32), (w, h): (usize, usize), out: &mut [i16], os: usize) {
         let (cw, ch) = (self.cwidth as i32, self.cheight as i32);
         let sh = self.log2_ctb - 1;
         let mask = (1i32 << sh) - 1;

crates/hevc/src/slicedec.rs

@@ -7,6 +7,7 @@ use crate::cabac::{Cabac, Contexts, init_contexts};
 use crate::error::{Result, ensure, invalid};
 use crate::inter;
 use crate::intra::{self, Refs};
+use crate::mvpred::PbGeom;
 use crate::params::{Layout, Pps, Sps};
 use crate::picture::{FrameRef, RefPic};
 use crate::slice::{SliceHeader, SliceType};
@@ -678,7 +679,7 @@ impl<'a> SliceDecoder<'a> {
         self.mark_edges(x0, y0, n, n, E_TU_V | E_PU_V, E_TU_H | E_PU_H);
         if skip {
             self.cu_intra = false;
-            self.prediction_unit(x0, y0, n, x0, y0, n, n, 0, PartMode::P2Nx2N, true)?;
+            self.prediction_unit(PbGeom { xc: x0, yc: y0, ncb: n, xp: x0, yp: y0, w: n, h: n, part_idx: 0 }, PartMode::P2Nx2N, true)?;
             self.finish_cu(x0, y0, n);
             return Ok(());
         }
@@ -707,7 +708,7 @@ impl<'a> SliceDecoder<'a> {
             }
             self.parse_intra_modes(x0, y0, n, part)?;
             self.max_trafo_depth = self.sps.max_th_depth_intra + self.intra_split as u32;
-            self.transform_tree(x0, y0, x0, y0, log2, 0, 0, [true, true])?;
+            self.transform_tree((x0, y0), (x0, y0), log2, 0, 0, [true, true])?;
         } else {
             self.intra_split = false;
             let mut merge2nx2n = false;
@@ -724,7 +725,8 @@ impl<'a> SliceDecoder<'a> {
                 PartMode::PNxN => &[(0, 0, h, h), (h, 0, h, h), (0, h, h, h), (h, h, h, h)],
             };
             for (i, &(px, py, pw, ph)) in parts.iter().enumerate() {
-                let merge = self.prediction_unit(x0, y0, n, x0 + px, y0 + py, pw, ph, i, part, false)?;
+                let merge =
+                    self.prediction_unit(PbGeom { xc: x0, yc: y0, ncb: n, xp: x0 + px, yp: y0 + py, w: pw, h: ph, part_idx: i }, part, false)?;
                 if part == PartMode::P2Nx2N {
                     merge2nx2n = merge;
                 }
@@ -738,7 +740,7 @@ impl<'a> SliceDecoder<'a> {
             let root_cbf = if !merge2nx2n { self.dd(RQT_ROOT_CBF) == 1 } else { true };
             if root_cbf {
                 self.max_trafo_depth = self.sps.max_th_depth_inter;
-                self.transform_tree(x0, y0, x0, y0, log2, 0, 0, [true, true])?;
+                self.transform_tree((x0, y0), (x0, y0), log2, 0, 0, [true, true])?;
             }
         }
         self.finish_cu(x0, y0, n);
@@ -912,7 +914,7 @@ impl<'a> SliceDecoder<'a> {
         Ok(())
     }
 
-    fn transform_tree(&mut self, x0: i32, y0: i32, xb: i32, yb: i32, log2: u32, depth: u32, blk_idx: u32, parent_cbf_c: [bool; 2]) -> Result<()> {
+    fn transform_tree(&mut self, (x0, y0): (i32, i32), base: (i32, i32), log2: u32, depth: u32, blk_idx: u32, parent_cbf_c: [bool; 2]) -> Result<()> {
         let split =
             if log2 <= self.sps.log2_max_tb && log2 > self.sps.log2_min_tb && depth < self.max_trafo_depth && !(self.intra_split && depth == 0) {
                 self.dd(SPLIT_TRANSFORM + (5 - log2 as usize)) == 1
@@ -937,10 +939,10 @@ impl<'a> SliceDecoder<'a> {
         }
         if split {
             let h = 1 << (log2 - 1);
-            self.transform_tree(x0, y0, x0, y0, log2 - 1, depth + 1, 0, cbf_c)?;
-            self.transform_tree(x0 + h, y0, x0, y0, log2 - 1, depth + 1, 1, cbf_c)?;
-            self.transform_tree(x0, y0 + h, x0, y0, log2 - 1, depth + 1, 2, cbf_c)?;
-            self.transform_tree(x0 + h, y0 + h, x0, y0, log2 - 1, depth + 1, 3, cbf_c)?;
+            self.transform_tree((x0, y0), (x0, y0), log2 - 1, depth + 1, 0, cbf_c)?;
+            self.transform_tree((x0 + h, y0), (x0, y0), log2 - 1, depth + 1, 1, cbf_c)?;
+            self.transform_tree((x0, y0 + h), (x0, y0), log2 - 1, depth + 1, 2, cbf_c)?;
+            self.transform_tree((x0 + h, y0 + h), (x0, y0), log2 - 1, depth + 1, 3, cbf_c)?;
             return Ok(());
         }
         let cbf_luma =
@@ -949,7 +951,7 @@ impl<'a> SliceDecoder<'a> {
         if depth > 0 {
             self.mark_edges(x0, y0, n, n, E_TU_V, E_TU_H);
         }
-        self.transform_unit(x0, y0, xb, yb, log2, blk_idx, cbf_luma, cbf_c)
+        self.transform_unit((x0, y0), base, log2, blk_idx, cbf_luma, cbf_c)
     }
 
     /// cu_qp_delta_abs / sign and QP update (7.3.8.14).
@@ -979,7 +981,15 @@ impl<'a> SliceDecoder<'a> {
         Ok(())
     }
 
-    fn transform_unit(&mut self, x0: i32, y0: i32, xb: i32, yb: i32, log2: u32, blk_idx: u32, cbf_luma: bool, cbf_c: [bool; 2]) -> Result<()> {
+    fn transform_unit(
+        &mut self,
+        (x0, y0): (i32, i32),
+        (xb, yb): (i32, i32),
+        log2: u32,
+        blk_idx: u32,
+        cbf_luma: bool,
+        cbf_c: [bool; 2],
+    ) -> Result<()> {
         let n = 1i32 << log2;
         let chroma_here = log2 > 2 || blk_idx == 3;
         let cbf_chroma = cbf_c[0] || cbf_c[1];
@@ -1284,7 +1294,7 @@ impl<'a> SliceDecoder<'a> {
                 max_y = max_y.max(yc);
             }
         }
-        self.reconstruct(x0, y0, log2, c, qp, ts, max_x, max_y)
+        self.reconstruct((x0, y0), log2, c, qp, ts, (max_x, max_y))
     }
 
     fn coeff_abs_level_remaining(&mut self, rice: u32) -> Result<i32> {
@@ -1303,7 +1313,7 @@ impl<'a> SliceDecoder<'a> {
     }
 
     /// Scaling, transform and addition to the prediction.
-    fn reconstruct(&mut self, x0: i32, y0: i32, log2: u32, c: usize, qp: i32, ts: bool, max_x: usize, max_y: usize) -> Result<()> {
+    fn reconstruct(&mut self, (x0, y0): (i32, i32), log2: u32, c: usize, qp: i32, ts: bool, (max_x, max_y): (usize, usize)) -> Result<()> {
         let n = 1usize << log2;
         let bd = if c == 0 { self.pic.bd_y } else { self.pic.bd_c };
         let coeffs = &mut self.coeffs[..n * n];
@@ -1355,19 +1365,8 @@ impl<'a> SliceDecoder<'a> {
     }
 
     /// prediction_unit(): parse, derive motion, store it and predict. Returns merge_flag.
-    fn prediction_unit(
-        &mut self,
-        xc: i32,
-        yc: i32,
-        ncb: i32,
-        xp: i32,
-        yp: i32,
-        w: i32,
-        h: i32,
-        part_idx: usize,
-        part: PartMode,
-        skip: bool,
-    ) -> Result<bool> {
+    fn prediction_unit(&mut self, g: PbGeom, part: PartMode, skip: bool) -> Result<bool> {
+        let PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx } = g;
         let merge = if skip { true } else { self.dd(MERGE_FLAG) == 1 };
         let mvf = if merge {
             let idx = if self.sh.max_num_merge_cand > 1 {
@@ -1382,7 +1381,7 @@ impl<'a> SliceDecoder<'a> {
             } else {
                 0
             };
-            self.derive_merge(xc, yc, ncb, xp, yp, w, h, part_idx, part, idx as usize)
+            self.derive_merge(PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx }, part, idx as usize)
         } else {
             let pred_idc = if self.sh.is_b() {
                 if w + h != 12 {
@@ -1426,7 +1425,7 @@ impl<'a> SliceDecoder<'a> {
                 if ref_idx[l] < 0 {
                     continue;
                 }
-                let mvp = self.derive_amvp(xc, yc, ncb, xp, yp, w, h, part_idx, l, ref_idx[l] as usize, mvp_flag[l] as usize);
+                let mvp = self.derive_amvp(PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx }, l, ref_idx[l] as usize, mvp_flag[l] as usize);
                 // mvLX = (mvp + mvd) wrapped to 16 bits (8-94)
                 f.mv[l] = [(mvp[0] as i32 + mvd[l][0]) as i16, (mvp[1] as i32 + mvd[l][1]) as i16];
             }
@@ -1524,11 +1523,11 @@ impl<'a> SliceDecoder<'a> {
             if bi {
                 let (w0, o0) = get(0);
                 let (w1, o1) = get(1);
-                inter::put_weighted_bi(&self.pred0, &self.pred1, bw, bh, bd, log2wd, w0, w1, o0, o1, dst, stride);
+                inter::put_weighted_bi(&self.pred0, &self.pred1, (bw, bh), bd, (log2wd, w0, w1, o0, o1), dst, stride);
             } else {
                 let l = if lists[0] { 0 } else { 1 };
                 let (wt, o) = get(l);
-                inter::put_weighted_uni(&self.pred0, bw, bh, bd, log2wd, wt, o, dst, stride);
+                inter::put_weighted_uni(&self.pred0, (bw, bh), bd, (log2wd, wt, o), dst, stride);
             }
         }
     }

crates/ui-egui/src/show.rs

@@ -739,84 +739,19 @@ fn keyboard(ctx: &egui::Context, show: &mut Show, doc: &Presentation, now: f64,
     let mut keep = true;
     let mut actions = vec![];
     for (k, m) in keys {
-        use egui::Key::*;
-        let presenter_grid = presenter && show.presenter_grid;
-        let grid_open = if presenter { show.presenter_grid } else { show.grid };
-        if grid_open && !matches!(k, Escape | Minus) {
+        let handled = if grid_open(show, presenter) && !matches!(k, egui::Key::Escape | egui::Key::Minus) {
             // See All Slides takes no other keys until a slide is chosen.
-            if k == G && plain(m) {
-                if presenter_grid {
-                    show.presenter_grid = false;
-                } else {
-                    show.grid = false;
-                }
+            if k == egui::Key::G && plain(m) {
+                close_grid(show, presenter);
+                true
             } else {
-                continue;
+                false
             }
         } else {
-            match k {
-                Escape | Minus => {
-                    let cancelled = k == Escape && show.clear_goto();
-                    if !cancelled && !show.back_out(presenter) {
-                        keep = false;
-                    }
-                }
-                ArrowRight | ArrowDown | Space | PageDown | N => {
-                    if show.ended {
-                        keep = false;
-                    } else {
-                        actions.push(show.state.next(doc));
-                    }
-                }
-                Enter => {
-                    if !show.goto.is_empty() {
-                        if let Some(i) = show.take_goto()
-                            && i < doc.slides.len()
-                        {
-                            actions.push(show.state.goto(doc, i));
-                        }
-                    } else if show.ended {
-                        keep = false;
-                    } else {
-                        actions.push(show.state.next(doc));
-                    }
-                }
-                Backspace if !show.goto.is_empty() => {
-                    show.goto.pop();
-                }
-                ArrowLeft | ArrowUp | Backspace | PageUp | P if !(k == P && m.command) => {
-                    show.ended = false;
-                    actions.push(show.state.prev(doc));
-                }
-                P if m.command => show.set_pen(!show.pen),
-                L if m.command => show.set_laser(!show.laser),
-                A if m.command => show.arrow(),
-                Home => {
-                    if let Some(i) = show.state.first_index(doc) {
-                        actions.push(show.state.goto(doc, i));
-                    }
-                }
-                End => {
-                    if let Some(i) = show.state.last_index(doc) {
-                        actions.push(show.state.goto(doc, i));
-                    }
-                }
-                B | Period => toggle_blank(show, Color32::BLACK),
-                W | Comma => toggle_blank(show, Color32::WHITE),
-                E => show.strokes.clear(),
-                G if plain(m) => show.open_grid(presenter),
-                Z if plain(m) => show.zoom_key(),
-                T if plain(m) => show.timer.toggle(now),
-                R if plain(m) => show.timer.reset(now),
-                OpenBracket if plain(m) => show.nudge_notes(-NOTES_STEP),
-                CloseBracket if plain(m) => show.nudge_notes(NOTES_STEP),
-                Num0 | Num1 | Num2 | Num3 | Num4 | Num5 | Num6 | Num7 | Num8 | Num9 => {
-                    if let Some(d) = k.name().chars().next() {
-                        show.push_slide_number(d, now);
-                    }
-                }
-                _ => continue,
-            }
+            navigation_key(show, doc, k, m, presenter, &mut keep, &mut actions) || tool_key(show, k, m, now, presenter)
+        };
+        if !handled {
+            continue;
         }
         // The same key must not also activate a focused presenter button or be handled again
         // by an embedded presenter viewport.
@@ -831,6 +766,111 @@ fn keyboard(ctx: &egui::Context, show: &mut Show, doc: &Presentation, now: f64,
     keep
 }
 
+/// Whether the grid that the presenter key G opens is showing in this viewport.
+fn grid_open(show: &Show, presenter: bool) -> bool {
+    if presenter { show.presenter_grid } else { show.grid }
+}
+
+/// Closes the grid that G opens in this viewport.
+fn close_grid(show: &mut Show, presenter: bool) {
+    if presenter && show.presenter_grid {
+        show.presenter_grid = false;
+    } else {
+        show.grid = false;
+    }
+}
+
+/// Keys that move through the show or end it. False when `k` isn't one of them.
+fn navigation_key(
+    show: &mut Show,
+    doc: &Presentation,
+    k: egui::Key,
+    m: egui::Modifiers,
+    presenter: bool,
+    keep: &mut bool,
+    actions: &mut Vec<ShowAction>,
+) -> bool {
+    use egui::Key::*;
+    match k {
+        Escape | Minus => {
+            let cancelled = k == Escape && show.clear_goto();
+            if !cancelled && !show.back_out(presenter) {
+                *keep = false;
+            }
+        }
+        ArrowRight | ArrowDown | Space | PageDown | N => {
+            if show.ended {
+                *keep = false;
+            } else {
+                actions.push(show.state.next(doc));
+            }
+        }
+        Enter => {
+            if !show.goto.is_empty() {
+                if let Some(i) = show.take_goto()
+                    && i < doc.slides.len()
+                {
+                    actions.push(show.state.goto(doc, i));
+                }
+            } else if show.ended {
+                *keep = false;
+            } else {
+                actions.push(show.state.next(doc));
+            }
+        }
+        Backspace if !show.goto.is_empty() => {
+            show.goto.pop();
+        }
+        ArrowLeft | ArrowUp | Backspace | PageUp => {
+            show.ended = false;
+            actions.push(show.state.prev(doc));
+        }
+        P if m.command => show.set_pen(!show.pen),
+        P => {
+            show.ended = false;
+            actions.push(show.state.prev(doc));
+        }
+        Home => {
+            if let Some(i) = show.state.first_index(doc) {
+                actions.push(show.state.goto(doc, i));
+            }
+        }
+        End => {
+            if let Some(i) = show.state.last_index(doc) {
+                actions.push(show.state.goto(doc, i));
+            }
+        }
+        _ => return false,
+    }
+    true
+}
+
+/// Pen, laser, blanking, zoom, the timer, note size and typed slide numbers. False when `k`
+/// isn't one of them.
+fn tool_key(show: &mut Show, k: egui::Key, m: egui::Modifiers, now: f64, presenter: bool) -> bool {
+    use egui::Key::*;
+    match k {
+        L if m.command => show.set_laser(!show.laser),
+        A if m.command => show.arrow(),
+        B | Period => toggle_blank(show, Color32::BLACK),
+        W | Comma => toggle_blank(show, Color32::WHITE),
+        E => show.strokes.clear(),
+        G if plain(m) => show.open_grid(presenter),
+        Z if plain(m) => show.zoom_key(),
+        T if plain(m) => show.timer.toggle(now),
+        R if plain(m) => show.timer.reset(now),
+        OpenBracket if plain(m) => show.nudge_notes(-NOTES_STEP),
+        CloseBracket if plain(m) => show.nudge_notes(NOTES_STEP),
+        Num0 | Num1 | Num2 | Num3 | Num4 | Num5 | Num6 | Num7 | Num8 | Num9 => {
+            if let Some(d) = k.name().chars().next() {
+                show.push_slide_number(d, now);
+            }
+        }
+        _ => return false,
+    }
+    true
+}
+
 /// Draw and advance the active show, handling hidden frames, timing, input, transitions, and
 /// presenter/reading presentation.
 pub fn ui(app: &mut SlideApp, ui: &mut Ui) {

packaging/windows/deckcraft.wxs

@@ -58,9 +58,15 @@
       <Component Id="DeckcraftApp" Guid="D87EA444-41A4-4C19-922E-66D1A29461FF">
         <File Id="DeckcraftNotice" Source="$(var.BinDir)\NOTICE" KeyPath="no" />
         <File Id="DeckcraftExe" Source="$(var.BinDir)\deckcraft.exe" KeyPath="yes">
+          <!-- No Icon here, so the shortcut shows the icon embedded in deckcraft.exe (build.rs). An
+               MSI Icon is cached under %APPDATA%\Microsoft\Installer\{ProductCode}\, and every
+               update is a major upgrade with a new ProductCode that deletes the old folder. A
+               taskbar pin is a copy of this shortcut that the update never touches, so it kept
+               pointing at the deleted file and lost its icon (#1114). The exe's path survives
+               updates; the shortcut is not advertised, so it targets that path and its icon is the
+               exe's own. The Icon above stays for ARPPRODUCTICON (Apps and features). -->
           <Shortcut Id="StartMenuShortcut" Directory="ProgramMenuFolder" Name="DeckCraft"
-              Description="DeckCraft presentations and slide shows" WorkingDirectory="INSTALLFOLDER" Advertise="yes"
-              Icon="DeckcraftIcon.ico" IconIndex="0" />
+              Description="DeckCraft presentations and slide shows" WorkingDirectory="INSTALLFOLDER" Advertise="no" />
         </File>
 
         <!-- .deckcraft: DeckCraft's own format. -->

packaging/windows/package.ps1

@@ -83,6 +83,15 @@ foreach ($check in @(@('deckcraft.exe', 2), @('deckcraft-cli.exe', 3))) {
   if ($h.Subsystem -ne $check[1]) { throw "$($check[0]) has PE subsystem $($h.Subsystem), expected $($check[1])" }
   Write-Output "ok $($check[0]): $Arch, PE subsystem $($h.Subsystem)"
 }
+
+# The Start menu shortcut is not advertised and names no MSI icon, so it shows the icon embedded in
+# deckcraft.exe (#1114). -SkipBuild takes whatever binary is already there, which may come from a
+# build without DECKCRAFT_REQUIRE_WINRES=1 whose resource compilation failed: refuse an exe with no
+# icon instead of shipping shortcuts with a generic one. ExtractIconEx with index -1 counts them.
+Add-Type -Namespace DeckCraft -Name Shell -MemberDefinition '[DllImport("shell32.dll", CharSet = CharSet.Unicode)] public static extern uint ExtractIconEx(string file, int index, IntPtr[] large, IntPtr[] small, uint icons);'
+$Icons = [DeckCraft.Shell]::ExtractIconEx((Join-Path $Bin 'deckcraft.exe'), -1, $null, $null, 0)
+if ($Icons -eq 0) { throw 'deckcraft.exe has no embedded icon: rebuild it with DECKCRAFT_REQUIRE_WINRES=1 (omit -SkipBuild)' }
+Write-Output "ok deckcraft.exe: $Icons embedded icon group(s)"
 $Stage = Join-Path $TargetDir "windows-package\$Arch"
 Remove-Item -Recurse -Force $Stage -ErrorAction SilentlyContinue
 New-Item -ItemType Directory -Force -Path $Stage | Out-Null